Here are two videos featuring easy strats for two of the more trickier bosses in the game (also you don't have to rely on RNG anymore to get a good run. The whole hoping the turrets give you a ton of extra lives thing~)

Miracle Man: What's shown in the video is easy to understand, just keep up the rhythmical mashing of your attack and you'll be good. If you mistime it or your positioning on the initial hit is off, Miracle Man will escape the loop.

Mr M: If you make contact with the boss (the ship) you'll only take 2 damage and you will have I-frames, allowing you to avoid the insta-death projectiles with ease. Additionally, make sure your attacks are quite frequent or else you'll have to deal with an extra cycle.

I did the Miracle Man lock in practice quite a bit, but in my run I couldn't seem to get him locked in. Wish I knew the Mr M iframe trick earlier lol, I lost a lot of runs to the insta death. Great info!