My first playthrough went without any kind of bugs at all, really robust engine from what I've had the pleasure of experiencing!
There's a few super minor things which I don't know if you would class as bugs but I'll report them anyway for the sake of being thorough:
1) Sometimes when standing alongside wall tiles, the tiles will be drawn over the character, but then the adjacent tile is drawn under. I don't know how unavoidable this is with your z axis stuff, but I only really noticed this with this particular style of rock tiles at a few spots in the first segment of the game. I may not have been paying as much attention to it after becoming more familiar with the game (cause it's really cool) 
2) In the Orobas dialogue immediately prior to the bossfight, I think you may have misspelled "Psyche!", it currently reads "Pysche!"