Most of the game is just a slow version of VVVVVV, with the checkpoints and the one-hit deaths. And at the end, the keys are quite difficult to get, and require a LOT of backtracking. The ending is well built-up to, as more and more glitchy things happen as you approch the end of the game (although their really ISN'T any ending, as you're just left with a glitchy screen and an impossible to get teleporting key).
But besides these things, most of the game's timed puzzles are very nice, and not overly difficult. Although the game only has one looping music track, I feel as if it does fit quite nicely with the dark and helpless, but not creepy atmosphere of the game.
Over all, this game is okay. Just as long as you have A LOT of patience, and are willing to backtrack through tons of loops for a disappointing ending that doesn't really have anything to do with anything else in the game.