Defend your planet (4K)

Another game I am working on for the 4K.

http://marber8.freehostia.com/defend.jnlp

Pretty simple so far. Use the mouse to rotate your shield around the planet to protect it from incoming asteroids. Each hit that the shield takes reduces its size a little bit. If an asteroid makes it to the planet the shield reduces by a larger amount. Your shield will never go below a certain minimum size. It also regenerates continually, so it will eventually get back up to size if it has a long enough rest. I will also go back to maximum size between levels.

I am thinking of adding a laser type canon and a bonus level that occurs every 5 levels to add a bit of variety. I have about 1500 bytes left, so I should be able to fit that in.

All comments are welcome.

Thanks.

I managed to pause it (P, I think) and I can’t unpause it! I’ve tried P, U, Esc, then every letter in the alphabet.

There must be a bug, because there is no pause key.

Ok, I’ve experimented and I can reproduce it by pressing Esc. No stack trace is produced, so it seems to be returning from the main loop rather than throwing an exception.