Suite Macabre, a homebrew platformer/adventure game. Need to defeat the three bosses. Have to do a few things to get the key to each boss door. I found a floor clip with stairs. If you hit Up then Down on the next frame after starting to climb, you start climbing down thru the floor. Only useful in a few places, most of the stairs take you to an OOB room which leads back to the start of the game. The biggest one is to grab the silver key without getting the fuse and going all the way around.
I also happened to underflow my health, tho I was unable to replicate it. Seemed like I maybe did several frame perfect jumps off the ground after dying, so it skipped the death animation, that was my only thought.
https://www.youtube.com/watch?v=4y9YfYBmb1k
RTA run -
https://www.youtube.com/watch?v=jBxixXYBV3g