This is really impressive for a two person project in UE! Great job you two!
Critical Feedback:
I noticed a couple of bugs: A lot of the purple goo after the first section doesn't seem to generate overlap events (So you can just run through it). I also got a complete crash on the boss fight. If I had to guess, it was because one of the minions projectiles hitting the boss? But that's just a guess. It occurred when I ran to the back of the arena to get a stamina potion, but crashed before I got there, so it's not related to the pickups I don't think. Sorry, I should have screenshot the crash log for you.
Other than that, my only criticism is that some visual feedback on the player when they get hit would go a long way, and also that the platforming section after the first key is a little tricky given the jump height. Also, it was a little tricky to hit the slimes and not get hit back sometimes. Maybe if they had a slower melee attack that was easier to bait out? But I totally get you probably didn't have time for that.
Positive Feedback:
The presentation is amazing, the character controls are really nice, and I love the upgrades hidden around. Some optional content was really nice to see, and I love the design decision to make the potions in the boss arena not trigger the pickup animation to keep you in the action. Also the Widgets were really nice, and I know how painful widgets can be with UMG.
Aesthetics are amazing, I love the shader work, the outlined effect is awesome. The intro sequence is beautiful. The enemy design is also really really nice, and so is the character and it's animations. I love the small touches too, like the bridge made of coloured pencils in the beginning, and the coloured drawings implying the narrative.
Sound design was also really good, the SFX on the player attacking were nice, and the music was fitting.
This is an insanely impressive game for a two person team, especially in UE. You two should be really proud of this. I would love to see this expanded upon into a full game. I really enjoyed this, and I think you could definitely push this into a full release for steam. There is such a solid foundation here.
If you get a chance, would really appreciate if you checked out our game for some feedback too, but no pressure. I've followed both you on Itch and will definitely be keeping on eye out for anything else you release.