Friday, September 30, 2005

Rant: Passwords

If you have read some of my previous blog entries, you know that I am not a fan of passwords as a method for keeping track of a player's progress. They are annoying, especially if you are stuck on a tough level. Also, they are unnecessary; just save the player's state to disk, or better yet allow the player access to every level. I do not like passwords, but I put up with them. However, there is a more nefarious password system which some puzzle and logic games use: the password every fifth level system. In these games, some sadistic designer or program decided it would be a nifty idea to only handout passwords after the successful completion of every fifth level. The effect of this is that if you get stuck on level 23, when you return to game, you have to repeat levels 21 and 22 before getting another crack at level 23.

This week, I am going to tell you about three games which use such a password system. The sad part is that these are otherwise very good games. Please do not download them. It will drive you crazy that such good games have been ruined.

The Pickles

Your goal is to get each pickle to an exit. Standing in your way are various blocks which the pickles can push around. Or by gaining one of three special powers, pickles can pull blocks, break blocks, or fly over them. You also have to avoid the "enemies" on your way to the exit. There are fifty levels, and they are of high quality. The interesting aspect is that the pickles often have to work together: one pickle moving a block so that another can get to an exit. Passwords every five levels completely ruins a potentially great game.

Mushroom Man

The usual thing: get Mushroom Man to the exit. The obstacles include locks, guards, holes, water, and walls. To get around these obstacles there are keys, money (to bribe the guards), cement, oxygen tanks, and bombs. The teleporters are often handy. The levels are well designed. The designer often toys with you by placing unnecessary tools about to throw you off the trail. Mushroom Man contains 150 levels, I think. I only completed 85 before the password every 5 got to me. Ugh.


This one is slightly different. Passwords are given out every six levels. In Atomic, your job is to form the target molecule by moving the atoms around. Moving an atom causes to slide until it hits a wall or another atom. I did not get very far in this one because there is another version without this silly password system.

Friday, September 23, 2005

6 Colors

Title: 6 Colors
Author: Pvya Net!
License: Freeware

The people who brought us Pyva Lights are back with another addicting way to kill five minutes. 6 Colors is a two-player strategy game of territorial conquest. You start with one little region in the lower left corner. The computer starts with one region in the upper right corner. Each turn, you choose one color to annex. Any region of that color which is adjacent to or connected by like color regions to your previous conquests becomes part of your empire. Then the computer chooses a color to add to its empire. The one catch is that you cannot choose the same color which you or your opponent chose on their last turn. The first player to conquer more than half of the regions, wins the game.

Here is a typical starting position. My empire consists of the one blue region in the lower left; the computer has the one orange region in the opposite corner. I have to choose one of the four other colors to annex. Purple looks like the goer as this adds two regions. Just click on the purple square at the bottom. The game precedes pretty quickly. The strategy in 6 colors is quite interesting. On this board, I see a long yellow chain not too far from my starting position. This provides a serious inroad to the middle of the map. So, I will try to get there a quickly as possible. Besides trying to take areas, you try to block your opponent and shut off areas of the board.

Here is the same game a little while later. By raw count, I am behind slightly: 39% to 41%. However, I have cut off the lower right corner and will eventually get those and win the game.

Games take only five minutes to play. The computer opponent puts up a good fight, or you can play against another person (hot seat fashion). There is a bit of luck in the initial layout of the board. However, after playing a game, you can flip the board and play the game again from the opposite side. This eliminates the luck factor.

6 colors is a wonderfully addicting game, but it does have some flaws. First, you have to play with "autofinish" (under options in the menu) turned on. If you do not, you can end up in these stalemate situations where the computer will not finish off the game and claim colors completely within its boundaries. This is probably the result of a horizon effect in its min-max search. This is a shoddy piece of Q&A testing.

Second, once the computer gains more than 50% of the board, it stops the game and tells you that you have lost. I wish you could finish the game. In a flipped game, you often what to know by how much you lost. If you won the first game with 60%, you want to see if you get more than 40% in the flipped game.

Third, sometimes it is hard to tell which regions are connected. From time to time, I made a few mistakes thinking that regions were connected when they were not. I wish you could right click on the board and get a magnified display of that area.

There is an abstract strategy game called blokus which has similar tactics. You can play a java version on-line at their website

Friday, September 16, 2005

MisAdventures of Sir Randolph Doogleberry, British Explorer

Title: MisAdventures of Sir Randolph Doogleberry, British Explorer (MASRDBE)
Author: acoders
License: Freeware

Every now and then, I run across a game which I like despite its obvious flaws. MASRDBE is just such a game. It is not a particularly original idea for a puzzle game. There are not many levels, and they are fairly easy. As an added bonus, the game is a little buggy. Despite all of this, I really enjoyed playing MASRDBE. There is something about playing this game which is pleasant. I cannot explain it.

The goal in each level is to visit all of the yellow tiles exactly once. When you move off a yellow tile, it depresses, and you cannot return to it. You have to find a path which visits each one once. There are also white tiles which you can visit as often as you like or skip entirely. Sometimes, there are red and blue tiles which come in pairs. Stepping on them teleports you to the other tile of the same color. You may use these teleporting tiles as often as you like.

The tough part about the game is that you cannot take back a move. If make a misstep, you have to restart the level. And, the game keeps track of how many tries you make on each level. So, you have to think ahead. That said, the levels are quite easy. There was only one (level 23) which gave me any trouble. On few other levels, I had D'OH! moments when I made minor missteps, immediately saw what I had done wrong, and had to restart. There are only 45 levels in the game. Experienced logic gamers can finish this one off in two or three sessions.

MASRDBE is a little buggy. Nothing serious, but on few occasions it would not register my mouse click. Worse, when I completed the last level, it cleared my scores for all the levels. But, I was done, so who cares.

The levels in MASRDBE convert nicely in a mathematics problem: finding a Hamiltonian path in a graph. The yellow tiles correspond to the vertices of the graph. The allowed steps, properly taking white, red, and blue tiles into account, correspond to the edges. Here is the graph for the level shown above in the screen shot.

The Hamiltonian path which visits each vertex once corresponds to the path you need to take to complete the level. In general finding Hamiltonian paths is an NP-complete problem. However, due the relatively low degree of the vertices and the nice local structure (nearly planar), finding Hamiltonian paths in these graphs is not hard. The low degree keeps the number of options limited at any point. The local graph structure makes it easy to notice when a partially completed level is impossible. This is why MASRDBE is not a super challenging game.

There are several other games based on the same idea as MASRDBE. Here are three. First off, acoders has made a 3D version of MASRDBE. The same basic idea but from a third person 3D perspective. They also threw in a time limit.

Next is Sensitive. It is very similar to MASRDBE except its analogue of the yellow tiles disappear after a second or two. So, you cannot stand on a yellow tile thinking about what to do next. Also, if you hit one too many arrow keys, you fall off and die. Sensitive requires slightly more nibble fingers than MASRDBE.

The last is Comboling. This is a flash based game which you play in your browser. Your goal is to find a path which passes through each square once. Be sure to "change interface" to make diagonally related squares easier to detect.

Friday, September 09, 2005


Title: Babala
Author: Pavel Richter
License: Freeware

Babala is wonderful present from one person to all us logic game fans. In each Babala level, you have to dispose of several enemies, called balabaks. In each turn, you can move, shot, and/or lay mines. Then the balabaks move. If one reaches you, you lose. Simple enough, eh? One problem is that you usually have a limited supply of projectiles and mines. You cannot waste ammo in this game. Luckily, there are often weapon caches sprinkled about. You just have to get to them to rearm before the balabaks get to you. Levels can also include dynamite, time bombs, explosive barrels, bomb catapults, teleports, and the always fun dragon's head.

Here is a sample level. I picked this level to show because it is the first one with which I really had trouble. You need to kill all the green and red balabaks. Green balabaks have a range of four. Red balabaks have a range of only three, but require two shots to be killed. In this level, shooting a barrel sets off a chain reaction which opens up a corridor which allows you to access the balabaks. This also opens up a corridor for the balabaks to access you. Every time I tried this level, the balabaks overwhelmed me. Then, I realized that with a few shots I could create a little cave to hide in and force the balabaks come at me one or two at a time.

The game includes a scoring system. The quicker you solve a level, the higher your score. For the first 50 levels, high scores and par scores are included for comparison. On the above level, my score was far below the par score. So, there must be some way to beat the level without creating the cave, but I cannot figure out how.

There are 200 levels. You have to complete each level in order to advance to the next. However, you can pay a 50 point price to skip a hard level. Roughly, this allows you to skip one in every four levels. The early levels are easy. The later levels can be quite hard.

Babala is currently in beta status, and I have some suggestions which might improve the game. First, the variety and pacing of the levels is not great. Some of the levels are quite similar. Editing out these near repeats would improve the game. Also, some minor reordering might help.

My next suggestion has to do with the high score list. Version 0.2 of the game contained 125 levels, but it contained par and high scores for every level. Version 0.3 only contains par and high score for the first 50 levels. Also, sometimes the par score is higher than the high score. I assume that these are oversights which will probably be corrected. It would also be nice if you could upload your high scores. In reworking my way through the early levels to get that screen shot, I managed to beat the high score on 20 levels. I want credit.

My last suggestion is to include the ability to go back and replay completed or skipped levels. This would allow you to take another crack at a level where your score is significantly below par. Or, for the hardcore, figure out how to match the high score. For the levels you skipped, maybe you could gain back 25 points of the 50 point penalty by solving it later.

There is one aspect of the game which I do not like. The movement rules of the balabaks are not always easy to predict. Even after playing through all 200 levels, I cannot always figure out how they will move. As best I can tell, the movement algorithm is to have them move one at a time starting with the closest one (how are ties broken?). I think they use some truncated version of A* algorithm to find shortest path from the balabak to the player if close enough and follow the first so many steps. But among equal length paths, which one is taken? Consider this level

where you have one mine to place. Should you place it to the right or down? And when then there is no path from a balabak to the player or too many obstructions, it is very unclear how they decide to move. The movement in this case is not random, but I never could never nail down the algorithm.

Minor complaints aside. This is a great game. Pavel, thank you for making Babala for us.

Sunday, September 04, 2005


Title: Aura
Author: Tursiops Truncatus Software
License: Freeware

First off, this game has nothing to do with AURA: Fate of the Ages. Second you may notice that there is no screen shot. That is because no screen shot is possible for this game. When you start Aura, your screen goes blank. All of the feedback to the player is oral. Even the menus are oral. It is a fascinating idea. In truth, Aura is not the greatest game, nor is it complete, but the concept makes it worth trying.

The goal of each level is to make your way to the exit. The game is played on a rectangular grid. By hitting an arrow key, you move in that direction, but you cannot see where you are or where you are going. Instead, you get audio feedback. When you take a step, you hear a footstep. If you run into a wall, you hear a thud. There are doors to open, keys to find, rocks to push out of the way, pits and mines to avoid, and ice to slide on. Each has its own sound.

Keeping track of where you are is the hard part. As I played, I sat there with head down and eyes closed, creating a mental map of the level. This is surprising hard at first, but you get better with practice. By playing Aura, I felt I stretched my mental skills in new direction. It is like having to use a certain muscle for the first time. It hurts a little at first. I would highly suggest you resist the urge to get out a piece of graph paper and map out the levels as you are exploring them. You would be missing out on a key part of the game.

Aura has been in "Final Beta" status for two years now. The game contains only twenty or so tutorial levels. It is clearly not complete, and I fear that this is how it will end. It does come with a level editor. A few user made levels are available. The level editor does allow you to cheat and see the levels. You can also see that there are some items which never made it into the tutorial.

For more audio only games, here is a website to look at.