When I first booted up R, it looked like a mediocre Knytt wannabe, but there’s a lot more there than meets the eye. Sorry to be mysterious, but you have to experience it for yourself. It may take a bit of trying (especially with the slightly too-slippery controls), but once you get into it, it’s a trip.
The game’s missing a few levels in-between (it’s v0.9 and will be forever), but it’s playable from beginning to end. Your accomplishments are automatically saved if you quit the game.
By the way, this is from the guy who made Soldat.