A list of my thoughts (both good and bad):
Bad:
- I find the player taking damage from their own attacks a bit frustrating.
- The enemies need more juice when they get hit or take damage, make them squash and strech, spawn some particles and flash (change their color to white) for a bit and some impact sound, as it is the hitting action feels dull.
- Making the player start from 0 inside the tutorial is extremely brutal (after finishing the tutorial I can see why you did it (the game is just the tutorial), but for a later version I recommend you to create some sort of a checkpoint between sections. For example I died in the pit where you need to press shift to go over, because I didn't notice the shift text).
Good:
- The potion mixing mechanic is cool, a bit confusing as it is right now, especially in the moment when I combined 2 potions and they exploded, there were some signs on the ground, but it's hard to tell exactly why and what potions would explode or not if mixed together.
- The art is simple, but it works as it is (except the potion fluid/area on the ground, the big pixels make it look out of place, maybe add a different sprite, that has the same pixel size as the player and enemy sprites)
- The loading screen, be it simple, I do enjoy it. And the death screen is really cool (even though I would like to see it less :D (aka not dying so often).
I have to say the game still needs work, but I can see how it could become fun if you polish it, expand upon the good mechanics and take care of the frustrating parts.
I'll give you a 4/5 for encouragement. Good luck with making it better!