I am working on an improvement to this. Currently I'm 11 Frames ahead of the published run and just finished level 5.
Here's the WIP (you need Bizhawk and the patch for the game)
But now I ran into a serious problem: I'm losing my entire lead in the transition between levels 5 and 6. I can confirm that it's not because of additional lag, the overall lag counter still has a difference of -7 for my run before and after the transition. So my only other theory is that there is a really dumb frame rule.
Generally, this game makes no sense. First of all, every second frame is a lagframe. Some levels are full of lag that can only be removed by seemingly random variations of input, while others have no lag at all. The level I just finished is one of the latter and I couldn't gain a single frame, every slight change from was0x' strategy resulted in taking more damage or missing jumps.
I would really appreciate any help on this problem, I was so hoping to finally have a submittable TAS :/