Really fun and challenging game! I love the pixel art, music, sfx, and the upgrade system. I played as a mage first and enjoyed it so much I went back in as the warrior. It was tough, but if it were too easy, where would the fun be in that? Such a well-rounded game.
If I had to suggest anything, it would be a bit more story — even just a more exciting payoff at the ending would have been a nice reward after working so hard to seal the portals. I know that’s a lot to ask in a jam timeframe, so just some thoughts if you ever expand on it. The core gameplay was solid and super fun to play.
Also, sealing portals works well with the theme and didn't take it too literally, and I really enjoyed that aspect of your concept. It mixed things up as most games did take it pretty literally, myself included!