The checkpoint and lives system is pointless and just adds more frustration to the game than is necessary, especially considering you can continue endlessly. Sending the player back a room is just aggravating, especially when it happens after so few tries and just as I was starting to suss out a solution. The scanner is also hard to figure out, its never explained how its useful, the player is just told it is.
I like whats there a lot! It has the same quality that I liked about VVVVVV (taking a simple concept and remixing it over and over again) but the above issues keep me from wanting to complete it.