Very impressive stuff, I had no idea 3d was possible in the newer versions of rpg maker, and the 1 bit graphics made it look great. It reminded me of beyond the labyrinth, a dungeon crawler for the 3ds that I've played very very little.
As others have mentioned, level 2 can be a bit tricky with the monster stun-locking you in place, it took me a while to get through that part. About levels 3 and 4, I had a small issue with timing my hits where I had to press the button way earlier to get the marker in the blue section, I don't know if it's a bug or rpg maker web builds not being very good in general, if I have some time I'll test the downloadable version
I liked the way this controls, you can kinda buffer turning as you advance so that makes movement feel smoother and not as limited as in old megami tensei games and similar stuff.
The way the ost picks up made me think that initially I was running out of time in the first level, and at the same time reminded me a bit of corpse party, which is neat.
Overall, great job, I feel like this has lots of potential to be fleshed out with different mechanics and turned into a full/longer game