I find weird you did not level once (unless there's a bug). It should be 10 enemies of your player level to gain +1 lvl. I want the player to manage his floor level to find a cruise spot to farm xp, but let him fight lower/higher enemies if he wants to.
I played it again today, and I figured out what happened. I had no idea that all your levels reset per dungeon run, and I always got killed before levelling up due to go to higher dungeons too quickly. Oops.
I started in RPG Maker because at the time it was (and still is) the engine I knew the most. I'm not making things easy but I'm not sure I could manage the transition right now
I think it depends on how much extra mechanics that aren't default to RPGMaker you want to implement. If you're fine with what you have right now (or a little more) it probably doesn't make sense to switch. But I can't imagine it being too hard to recreate this in Godot if you'd ever want to switch engines.
Anyways, good luck with the further development of the game!