Really great stuff!
I didn't really notice a major difference with different characters and that wasn't a bad thing.
The only aesthetic advice would be to somehow make collectable items more apparent. There is usually so much going on in any level that collectibles can be hard to discern, especially if you have the spell that leaves flames behind the character walking path.
It would have been more enjoyable if backtracking was more rewarding, specifically the raven power up and accessing areas that were inaccessible previously.
I can completely understand if that would make the scope of the project overwhelming. I just saw open areas at the top of some dungeons that were inaccessible to a character and wanted them to lead to a new level if I had the raven.
I did really like the ability to backtrack.
The inventory was a little awkward to manage with the limited space but I think it explains itself well after a few playthroughs.
The tutorial gave the equipment for combo bonuses. It again took several playthroughs for that to really become apparent.
It might not be a bad idea to be a little more "hand holdy" for the first few areas and don't give too many spell choices. Then again, if the player is invested they will hopefully figure it out.
All in all, this is a really great project that should do really well.
Thanks so much for developing!