Happy people are downloading it and attempting the same in other languages! In Java it's a bit more difficult... But you can make code really short when you compress it by hand!
It's really hard to do what you did in java. Just the code for the window and keyboard input will probably consume about 512bytes. I remember there was a contest before, called java4k, although it's pretty much dead now, I tried to get some source codes of the games they used to create for that contest and I found 1 guy from who I learnt about "pack200". So using proguard + pack200 I managed to make 1.99 KB.
What is interesting is that Notch (creator of minecraft) managed to do Meg4kman in under 4KB. I don't know how he did it considering that it has enemies and 25 levels, it's pretty much a bigger project than this one. It's amazing!