Sweet game! However, the bounding box of the spaceship seems to be a bit too big since they don't visually collide but the game is over when they are clearly at least 5-10 pixels apart.
I changed the images so that they don't have any unnecessary space on the edges now which should help a little, and I also moved collision checking to the beginning of each update so that should help as well. The updated version should be in the downloads section.
The number of Aliens increases each level until you die or the game crashes
Wow, that was smart! Challenging a bunch of programmers to crash your game through skill! Brilliant! Now I gotta try it! xD
Thanks, it was a quick way to add more game play without actually adding more game play

Unfortunately I haven't been able to crash it yet (I suck at my own game)
Thanks for trying it guys

I appreciate the feedback