I sat down with Biohazard Battle again briefly this evening and you're all correct: Yellow ship is definitely the way to go! I breezed through the first few levels, finally getting defeated by the level 4 boss. I didn't have time to go through level 4 again, so I turned it off, but I'm feeling much more confident on the game now.
Finding time to game is so much harder now! Especially retro stuff, which takes a bit more commitment. I need games I can play one handed while cradling my daughter, haha