It's a really good job you've done in 3 days. With Multiplayer too at that (though I wouldn't know, I've got noone to coop with). Just impressive.
Only there are some things that quite honestly annoyed me: there are crystals that don't give you anything for your money/HP, and your money is reset each time you enter a new level (but that I could borderline overlook it by saying it's in the gameplay).
It doesn't change the fact that it's of high production value for a Jam game and I applaud you for it. While I didn't absolutely love it, I do think it could be a real fun game - I am not into rogue-likes and even less in level grinding so that means a lot from me.
I featured this game in my showcase video and touched 'Risk of Rain-like gameplay' for the first time:
https://youtu.be/PoWrHcmGjbU?t=7477