An NES game I started on because FHBG (for NES) was a buggy mess that I worked on more this year and finished. It's basically Bubble Bobble but with guns and a lot more variety.

Features:
* Tested to work on a real NES (as well as any emulator I've tried, even old 90s ones)
* Simultaneous two-player support (anyone can join in at any time) for co-op or competitive modes
* 52 levels
* Over 25 enemy types, plus a final boss
* Lots of different block types, including teleporters, spikes, moving platforms and toggleable blocks.
* 3 or 4 different level goal types
* Level editor
* Open source

Download (includes source; compiles with ca65)