!!Minor spoiler warning!! I found the platforming not too bad, but I feel like your stats are very weak overall. There was one dna upgrade that was too high for jump to reach, and it doesn't seem like there's double jump.
If you pick the wrong gun upgrades, I'm pretty sure there's no way you can beat Meadow (the mirror version of you boss). Way too much projectile spam from her and the hand summons, and I had inadequate damage to kill her summons quickly (I had 5 maxhp, 2 points into damage). I might try again going mostly damage.
The deer face boss is really hard. Took me 1-2 hours to beat him, even though he only has three attack patterns, because he just attacks so damn fast and there's very little room for error. That said, the experience was pleasant overall, though I think either the upgrades need to be stronger or more plentiful.