i played together with SchokoKeks and it was quite fun!
There was no latency problems. current system is quite solid except for a few little bugs... gameplay is a bit monotonous but, that could be improved with some ideas, like SchokoKeks already said, powerups, boss waves and such... i already made a lot of suggestions in-game, hope they were helpful.
I'd like to play again with more players, game is pretty fun at it's current state more people can be more fun, waiting for nex update