I agree in some sense that the game could be faster, especially when the game feels random because you don't know the patter. However, I think it's lacking more of a checkpoint at each level: you don't want to redo everything because you got caught experimenting. Moreover, the fact that you loose the instant they saw you is frustrating, you could add a small delay, a time to fix mistake and quickly back dash.
Apart, from that nice litte game, the atmosphere is quite here and i found no bug :)