Not sure if this is a bug, but sometimes that darn bullet spawns exactly where i stand, giving me no chance to avoid it. Also: What's the "Invasion" level about. Those ships don't seem to do anything... 
P.S. How do i make my own levels?
Technically... the bullet thing is not a bug since bullet spawning is completely random. But... I agree that can be annoying. I'll look into add some code to prevent that.
Invasion is a level to just rack up points if you choose. Every time you shoot down a UFO, you get points. They just fly around randomly; but if they touch you then you die... Is it worth the risk? It's your choice.
For now... if you want to generate your own levels. You need to have a good understanding of the LEVEL_Type data structure in jm_levels.h as well as the OBJECT_Type data structure in jm_objects.h. Then play around jm_level_data.c by tweaking a currently existing level to see what it does. Create the level pack by executing the jm_levels_make.bat. Also... for quick modification of a level you can define the macro USE_INTERNAL_LEVEL_PACK in jm_levels.c. Then create/modify a level within jm_levels.c. When you build Jumpman it will use the internal level pack and ignore the external level packs. This is the easiest way to generate and test a new level at this point. I wish I had a better answer for you.
I plan on generating some type of level maker... with instructions. I just have not had the time to do that yet.
