It's seriosly hard. Like, seriously, seriously hard. But not frustrating or annoying. It challenges your brain a ton, which I like.
I don't think it could pass as a masocore game, but the satisfaction you get from beating some of these levels sure reminds me of one.
Half of these levels will have you saying they're impossible, only to emerge victorious a couple dozen tries later, if you're patient and skilled enough, that is
My only complain is the bit of lag. It's completely tolerable, but it still takes away from the overall experience
All in all, it's awesome
I'm stuck on level 23 right now. I've come soooooooo close, haha!