It's completely undecided and will be decided together. Most likely 2D but if someone with modeling experience wants to help we can do 3D.
If it possible, I think it would be interesting to make a game similar to a custom map from Warcraft 3 with very simple gameplay, where every player choose builder, who may build "towers" or "buildings" of specific types, which spawn every N second creeps. Spawned creeps goes to attack enemies castle and also - have a limited life time. Simple game map looks like this, but it possible with two, one or four lines. I think it may be attractive in lowpoly, and it's easily to find necessery models (i know some assets from Unity with creeps). Also, I am have a little expirience in static modeling with 3DMax, so some building i could create).
Btw i talk about that custom map for warcraft3 https://www.epicwar.com/maps/301468/
