select a group of up to 20 units (easy if we do O(n^2) search, harder otherwise)
issue movement commands to those units (easy)
HOW TO DISTRIBUTE LOCATION UGH! (hard)
in particular, when player issues a move command, we only have 1 target for up to 20 units. How will we distribute their target locations so that they don't go on pathfinding overdrive or do something weird?
likewise, with attacking, 20 units can target 1 unit, they have all to find an open location within range of the target unit. This is hard for close-combat units like Zealots, but thankfully we don't have them in this demake. ACTUALLY, SCVs ATTACK JUST LIKE ZEALOTS UGH LOL WTF
start iterating on issuing movement commands to selected units. One challenge is do we want to make this "real-time turn-based" with discrete movement (popping between tiles) or real-time continuous movement? Latter is harder, so I guess that rules it out for now.