I tried BMX for some time but i did not like it that much... too much focussed in games, too limited but good and fast when doing prototyping and testing new ideas.
I joined some smaller bmx-coding-compos with funny rules!

here is a small bullethell-game (incl. src) but be warned... it's very optimized and strange because of a 4kb bmx-file-limit!
youtube & files

here is a small one-level-mario-game... without sound because there was a 12kb bmx-file-limit without any external files, everything (gfx & leveldata) is inside the bmx-file... don't try to understand the source!
youtube & files

I did not played bullethell_4k for years, I totally forgot how much I liked this one - maybe I will change BlutEngel II from level-based design to an wave-based shooter... space invaders meets bullethell. I believe this will work better with the limited screen (304x224), needs less checks (sprite vs. screen-bounds), scrippted enemies with better bullet-patterns...?