They've been playing their instruments in front of people for a whole year, and are now better than when they started. It would be nice to categorise their style of music, but it's proven to be a difficult thing. It's not Rock. And it's not Pop. It's neither and both, but only out of circumstance.
We reckon humans are actually clever enough to make their own mind up about this kind of thing, and nothing would ever change if they didn't, so go ahead, make your own mind up, it really is quite fun!