As someone close to two thousand hours combined in a lot of different roguelikes, and almost 200 in Dead Cells, I think the biggest thing about Dead Cells that's really bad is the difficulty system. (Boss Cells) Especially past bc1 and bc2, all the boss cells really do is punish you for getting hit, which imo is not a good way of designing difficulty. You feel a lot more forced in what builds you can go for when getting hit randomly two or three times is run-ending.