Haha, yea. Ranged ones will getcha as the range of of the weapons tend to increase with every stage.. I had trouble balancing it, so at a certain stage you get shot from enemies off screen :(
I think I've never made it past stage 8 so far.
I made the game from scratch using the Java version of Processing. It's Java+some libraries to make drawing stuff on the screen easier mostly.
Started with nothing and ended up with about 1.5k lines of spaghetti-code :)