Some criticisms I have are as follows: some of the weapons are either so good that it trivializes the game or so weak that they kill your run. Quiver/Cursed Magic (mainly the former) are good because you can shoot them and kill things off screen. One shot and sticky are terrible because they're too slow to kill anything while you're constantly moving to the right. Money eventually becomes useless and trying new weapons will likely end the run.
Otherwise, the game is pretty well designed and straight forward. Good art, music, sound design. It's sort of like playing Nuclear Throne but it's on a diet. Overall, this is quite poggers.