Loving the game so far--it's totally unique, and that feeling of something new is really fueling my desire to keep coming back. But there are a few things that kinda bug me:
-only 2 maps every 4 hours? Ummm... yeah, no. As far as Nintendo games go, I like how Mario Kart Wii did course selection: everybody picks a level, and the course is determined by a cycling "spinning wheel" of the selected levels.
-can't change weapons in between matches! Nintendo, you are so dumb /Antoine Dodson. I don't know about everyone else, but I kinda become "attached" to certain rooms (e.g. make rivals out of people who last splatted me... stuff like that). Because of this, I feel compelled to stick w/ a certain weapon longer than I ordinarily would due to the fact that, if I swapped artillery, then I'd be assigned an entirely new squad of squid to join. But even changing weapons can sometimes be a pain, because...
-no custom loadouts! I kinda like to change my tactics depending on the maps available, weapon types, etc.... but in doing this, I've got to scroll through the plethora of clothing options for each type. While it's not much of an issue on its own, when one only has a limited time for battling, I'd rather spend as little time as possible deciding what to wear ;P
So yeah, yay for negativity! Really though, overall I'm just head over heels w/ Splatoon. I really want game to completely take off and become Nintendo's next "big thing." The game delivers so many fun and fresh experiences and is only marred by a few inadequacies--its sequel could go a long way in addressing these relatively simple complaints.