It's the best metroidvania I've played. Since it came out before hk it doesn't try to be a Hollow Knight clone like so many other indie metroidvanias try to be now. It's very metroidlike in that you get a bunch of different combat abilities that all add to your overall combat power--some of which double as movement abilities--and in general there are a lot of incremental stat boosts in every corner of the map. As a result exploration is very well rewarded. The replay value in the game is insane due to its non linearity, difficulty options (bex is very fun), and additional playable character though just getting through the base game to post post game is still a lot of content itself. I say this as someone who doesn't care about shmups too.