Afogados really nailed it — the surprise factor when you actually play it is one of the best compliments a game can get, and the speed escalation that Sleeping Colossus loved is clearly doing its job keeping players on edge. The grey and red color contrast cattymations pointed out gives it a really striking visual identity, and the adaptive soundtrack building up like MOHMOH described adds genuine tension. Coyote time would be a game changer for the movement feel — even a few frames of grace after leaving a platform makes jumps feel so much more forgiving without removing the challenge. Camera positioning at the start being a bit low as Bl0ck head mentioned and the visual glitches at high speeds are the two main things worth addressing post-jam. The gravestone death animation Ogma Games highlighted is a great little touch too!
Feel free to check out my sky platformer too if you get a moment!