Currently at 93% completion.
Overall, great game with a few issues here and there with some manifesting in the form of weird bugs and glitches. Nothing fatal, which is good, but I've read numerous accounts of game breaking nonsense at reddit, so beware.
As others have mentioned, traversal can be a slog due to both map design and scant teleporter placement. There are no upgrades that allow for accelerated movement, either, so you're stuck in one gear plus the slide. Hit detection isn't 100%, but it's pretty close. Platforming has been the most frequent cause of death, due to both sloppiness on my part and frustrating design choices. I understand making pits and spikes deadly, but I personally would've preferred even a severe health penalty over making a slight error, only to have to return to the point of death from the last checkpoint.
The art is a huge draw. Character design, especially that of the bosses and larger entities, is absolutely spectacular and in some cases chilling. Some very satisfying secrets to be discovered as well. For the most part it doesn't bark hints at you, which I like.
Combat is good, if a bit limited in scope. Most everything can be vanquished with standard attacks, parries, and thrusts, but it keeps you on your toes nonetheless, especially in the second half.