Just played a bit and so far, it's quite interesting. I've just gotten the key from the switch-appearifying walls area, and the gameplay was simple but fun.
The dialogue was slow and mediocre at first, but I may have been overeager to start the actual game. The platforming and pixelmovement aspects were definitely something I've never seen in an RM game (just curious, were you using MGCaladtogel's script or one of your own?).
However, the impassability/collision could have been better; some points I was stopped by nothing (e.g. around the first pedestal), or hellhounds would walk right through me. It might've also helped the challenge to have a shadow, too, so you know where the player will land after a jump.
IMO, the 5 hearts system wasn't very effective either. It does add slight tension to the challenge, but forcing the player to start over if they make too many mistakes is not fun. Rather than a gameover screen, you could at least have the player restart a map. The monsters were also boring, but I understand an actual ABS would be asking for a lot.
Regardless, overall it was a nice play, and I'm looking forward to more, if you can address this bug I encountered: visiting the southern area before triggering the western area's cutscene probably screwed up some variables and got me stuck. After I found the key, I had no clue where to proceed and none of the areas (east) would open up.