This is pretty cool! The pixel art and the character animation is extremely well done! Like someone else said, CTRL and arrow keys together is an issue on macs. Freezing people and just pushing them around is surprisingly fun.
a mix of the both (freezing then pushing & controlling - or moving them against each other) is more or less the easier way to win (just controlling is quite harder)
about CTRL - during the weekend I'm going to add a second key (an alternative for CTRL) so to override this unexpected behaviour (sorry - I didn't check that :-|...)