I don't think it's fair to say it's overrated but each to their own.
I just like the way it forces you to face up each enemy, to understand how they're going to come at you and learn how to react to it. There's no button mashing here. Level design is decent as is the level up system but the game will punish you if you become lazy. Most games of this ilk you can disengage your brain and play through without much feeling; AAA, XXX, BBB, YYY etc. I think this is different and if you do complete a section or boss you feel like you've earned it and the game does reward you for it. I think it does what it does really well and it should be applauded. Bring on the sequel.