While STS has stated quite a few times that they made the game to be a 3v3 with 5 minute matches, it is still fun to speculate and come up with possible gamemodes.
I will share some of my favorite game mode ideas, and then you guys can share yours and we will have a nice hypothetical discussion, and hey, if we are lucky one of them might even become a real gamemode (I wouldn't hope though)

I start with my favorite gamemode idea, one where everything is the same except whenever you have a powerup your timer is paused. This would mean that once a player runs out of time they would have to stop the match but all the others would still play on as if nothing happened. I think this would be awesome, because suddenly sharing powerups are one of the key parts of the game, and rather than focusing towers you might get big 3v3 fights in the middle over who gets to share powerups.

Another idea is a one lane map, still 3v3 but with 3 towers per team and you get the powerups back at your base, and share them in the middle of the lane (which would be very hard)

So, what are your favorite gamemode ideas? Please tell me, because I love seeing all the creativity.