I just bought Hollow Knight the other day, during the Steam sale, although I'm not typically into platformers or metroidvania-style games. I was hesitant about the purchase, and I largely bought it because of the great reviews as well as I needed to spend $10 on something to use a coupon there. Well... I've sunk over 36 hours into it already in just a few days (I'm on vacation). Safe to say there are zero regrets about my purchase. It's super challenging, has very satisfying gameplay, and an interesting story, if not a little incoherent/hard to follow (at least to me anyway). Highly, highly recommended. It has a great sense of progression, fun exploration, and really good music as well. Also, seems to have quite a long play length, as I still seem to have quite a bit more game left at 36 hours in. Definitely worth checking out since you're looking for a game of this style.