New version up. This could be the final version. I think it will be available here:
http://java4k.com/index.php?action=games&method=view&gid=347

When is the exact deadline? I was hoping to add some more levels on Monday...

Also, if I submit now, can I upload a newer version later?

Thanks.

The orange is now a bit more reddish. I was hoping to avoid that, because it's so costly, but I agree that it was difficult to distinguish. :-/ I also fixed a bug related to the start/stop button. After my last change, it would restart the simulation rather than stop it.

There are two parts to the overlapping. First, when you draw over an existing track, it will remove the inactive one (grayed out a bit). Second, whenever a train leaves a square, the tracks switch (the active one becomes inactive and vice versa), even if the train didn't take the active track, i.e. when it enteres the inactive track from the other side. Note that it can happen that two trains leave a square at the same time, in which case it will look like the tracks didn't switch, because they switch twice.

Congrats to everyone who figured out all the levels. I've got some levels that are even more difficult. ;-)

Yeah, level 20 is hard. I'll probably move it further back to the 'really hard' section for the final version.

The middle of each square is now neutral, which hopefully avoids some of the jumping.

When it's playing, a click anywhere will now stop it.

I've still got a bit over 500 bytes; I could fit undo or instructions in there, but i've also got some other ideas that I'd like to do... and I want to add more levels of course.

I'm back with another game, yiihaaa. I admit it's a clone of an existing iPhone/iPod game. Find it here:
http://users.conquer-space.net/~ulfjack/trains.html

I'm doing my development on my MacBook, and I hope it works well on other machines. Let me know if it doesn't work for you. The other games basically don't work here.

This is still work in progress (I know I don't have a lot of time left), so feedback is welcome.

zeroone: Apparently, start() is _not_ called before paint(), so the offscreen buffer is not initialized. I've eliminated the start method and now check whether the offscreen buffer is null, and do the initialization inside paint. I've uploaded the new jar.

I've also seen glitches where webstart does not initialize the applet window to the correct size (it's way too small, looks like some default params). Then I reload and it works. Any ideas?

Oh, and level 5 can be done in 6 moves! 

And level 16 in 22.

Edit: Argh, should read the thread first. :-(

h3ckboy: They should come in immediately when you press enter. Odd. I've changed the Thread.yield to a Thread.sleep in the jar below. Could you be so kind and try that out?

zeroone: Could you try it again with a jar that contains debugging info?

I've got one here: http://users.conquer-space.net/~ulfjack/Critters4k.jnlp

kev: In the game or in the description? The blue guys are normal, the orange are fast, the black are slow, but strong, and the yellow ones fly. Something like this?

h3ckboy: You have to press space to start the first wave. I should have been more clear in the description about that...

h3ckboy: I'm sorry to hear that. Could you explain in a little more detail?

My girlfriend complained about the performance on her machine, which was apparently really bad for no discernable reason (she's got an Intel Core Duo with sufficient performance and the virtually identical software configuration as me). And she said that today's version was much better. I could try to use Thread.sleep instead of yield, maybe that would help?

UlfJack proudly presents: Critters4k

Critters are attacking your desktop! Set up your tower defense and let them come. 100 levels of mayhem!

Input:
 *  1, 2, 3, or 4 to select a tower
 * space advances to the next level
 * backspace restarts the game
 * left button to build or upgrade a tower
 * right button to sell it

http://ulf.ofahrt.de/critters4k/Critters4k.jnlp

I didn't expect to submit a game this year due to time constraints, but I've found the time after all (also thanks to the deadline extension). Feedback is very welcome. (Don't complain that it is too difficult. I've personally finished level 100. :-)

There's even another way to do level 5 in 10 moves:

The source for my games is also online, here:

http://ulf.ofahrt.de/4kgames/

Yay!

Well, the rule isn't clear. Are games not written in Java disallowed? In that case, Scala Pong should have been disqualified. Or is it just about the platform? In that case, Scala Pong should have gotten a fair judging, even if it's not much of a game. The problem I see is that the judging is not uniform (apparently the judges couldn't agree either). And I think that's unfair.

I'm in favor of allowing games written in other languages, because I think it would be cool and since a rule regarding the implementation language cannot be enforced anyway. I would propose a rule change that submitted games must only contain executable bytecode, no native code, and omit the language.

Alternatively, I would clarify that rule to say that games written in a language other than java are not allowed, and (retroactively) disqualify Scala Pong from the 2008 competition.

Some comments are odd. For example, 'no audio' is sometimes a technical lack, then a presentational, then it's in the overall column.

And I think it's unfair that one game wasn't properly judged (Scala Pong 4k). I know it violated rule gamma of the rule handbook, but since you can't verify whether a game is written in Java or any other language that targets the JVM, maybe that rule should be changed. For example, how can anyone say that spiderball4k was written in Java and not in Scala?

I'm rather satisfied that Thief4k got a good overall score despite lower technical and presentational scores. People liked it, but it didn't appear overly technical or presentational. I think that's a good sign.

It's damn cool! And I just finished the last level! 

New version with more levels is up!

I've just uploaded a new version with a new collision detection implementation.

Interesting, and good to know. So far no problems here though (and this machine is set to use UTF-8)...

Yes, it's much much better now. Very nice!

It's funny that the shooting sound is always a little late here...

Update: I've spent way too much time on a level editor. But anyway, a new version with three levels is online!!!

There are still some issues with collision detection, and it's a rather tight fit so far... so probably no new features.

I've just come across another way to insert binary data into the class file. Just define a string and use octal escapes for the characters. For example:

"\000\001\002\003"

represents the bytes 0 to 3. Then you can just do getBytes() on the String and get a byte array of the contents. Optimizers won't strip this String from the class file. There's a caveat however: String.getBytes() uses the platform encoding to turn the string into bytes. The platform encoding of (effectively) all platforms is ascii-safe, so you can use values 0 to 127 (inclusive).

It completely hangs here after every shot. I don't know if that's by design, but it's completely unplayable here.

I fully agree, and the next thing I'll be working on is a level editor. Hand-coding the levels into the source code is just not going to fly.  Better levels is #1 priority right now.

I was also thinking about a spring option, but it is going to be a tight fit.

PS: Glad you like it. :-)

Hi everyone!

I had an idea for a 4k game last sunday and have been coding the whole time (well, almost, only when I'm not at work obviously). I think it's feature-complete, and there are a couple of bytes left for levels.

You are a thief and your objective is to steal the rubies. But don't get caught by the guards! (Oh yeah, the dark gray thing is supposed to be a door. It's gonna be better in the new level layout...)

http://ulf.ofahrt.de/thief4k/Thief4k.jnlp

I didn't get my price yet.

Road Fighter is a endurance racing game, i.e. the goal is to drive a car as far as possible along a more or less straight road. Hitting other cars or the road border looses health, collecting ambulances gains health. Left-right to steer, up-down to accelerate and deccelerate.

Category: racer

Graphics:  1 simple geometric shapes
Technical: 2 collision detection
Gameplay:  2 basic, but addictive
Other:     
Total:     5

Problems:
There is a typo 'Press Spaca to Start'. I can't close the game by pressing the (x) button on the window. The game does not display the score when one looses (so I can't post my highscore). Resizing the window gives a gray area around the game.

Remark:
Road Fighter is mostly a fight against randomness. I had it happen that there were no ambulances for a long while, and in another run, a lot of them came right one after the other. Also, cars move rather erratically from left to right and vice versa, which makes it rather difficult to predict where they go. Additionally, sometimes very, very slow cars appear at the top and it is impossible to break or evade them.

Having said all these bad things about the game, how could one go about to make it better? By making it slightly more predictable, for example by having the cars follow the road exactly. Also, by having predetermined tracks (and possibly predetermined orderings of cars), for example by using a preset seed for the random number generator. Having predetermined tracks would allow to improve oneself by memorizing the track. Also, it might make the game fairer to have fixed intervals in which the ambulances appear (e.g. after 100, 200, 300, etc.).

In VOTA, the player controls an alien army invading earth. Of course, earth only has a single ship, and the alien army has quite a number of ships. Unfortunatly, the earth ship has infinite lives. Game control is ... err ... select a ship with left click, add waypoints with left click. Alternatively, remove all way points and set a new one with right click. Unfortunately, only one ship can be controlled at a time.

Category: shooter, sort of

Graphics:  1 simple geometric shapes
Technical: 1 simple collision detection
Gameplay:  2 clicky
Other:     1 sound (?)
Total:     5

Problems:
The top of the screen is cut off under linux.

Remark:
VOTA is an interesting idea, but I found the game rather difficult to control. There is no way to control multiple ships at once and the earth ship is behaving erratically, and not really predictable. Additionally, it's not possible to control directly when and where the alien ships shoot, rather they shoot only when they move and at certain preset intervals.

Note:
Check sound.

In Rottweiler 4k, the player controls a (big) black rottweiler on his mission to kill all the thieves in the pear orchard. Game controls are left-right, up to jump, space to clench jaws, and down and space to eat killed thieves (and restore ... energy or something).

Category:

Graphics:  4 it's amazing what one can do with all those simple geometric shapes
Technical: 2 seems a little more complicated than just simple collision detection
Gameplay:  1 repetitive
Other:     1 animated characters (dog,thieves)
           1 parallax scrolling
          -1 see remarks
Total:     8

Problems:
The top of the screen is cut off under linux (i.e. you can't see the health and the number of kills).

Remark:
Considering that this game only uses simple geometric shapes, the graphics are exceptionally well done. The one big downside is that thieves kicks can hit the dog even if he is in the air above their heads. Wtf?