Hi glad you enjoyed the game!
If it's not too much trouble, could you send me a screenshot of the "black smokey things"?
It would help me identify and fix the issue
na bro, its not about your game its about my monitor, it happens everytime but you can feel it much in games, and high contrasted dark areas. because everything has black outline, fast paced, and have some dark levels in game. while moving it feels like you re little dashing and leave a "smoke" behind as i say (like the dash animation in celeste) and it makes hard to keep your eye on platforms and everything. My monitor is msi and they were marketing it as a "most curved monitor ever" when i buy so it might be also effecting. But thanks for even asking to help.. (sorry for bad english)