Alright, let's cut to the chase: the best thing about this game is its stag beetle transit system. Seriously, look at that shit. That's cool as hell.
In addition to being a game with sick stag beetles, Hollow Knight is also a sprawling adventure that takes place within the decrepit remnants of bug kingdom. The game's muted color palette, lack of clear directions on how to proceed, and punishing level of difficulty contribute to an oppressive atmosphere that permeates the world's maze-like structure.
At times, Hollow Knight can feel needlessly frustrating, with some design decisions resulting in tedium instead of a genuine sense of challenge (needing to spend a talent point to fully utilize the game's map is silly). More often than not, however, the challenges are of the tough-but-fair variety, and even the smallest victories can feel triumphant. The game's slow pacing withholds instant gratification and demands patience, but hey, I have a lot of free time at the moment, so I'm willing to make the investment here.
And the stag beetles!