Thank you! Yep, the turn order is a big question now. I am currently thinking between two options:
1) Make it full-turn-based, where each player executes the full turn, and it will be a bit like an old good "Worms" game (I think we are already accidentally close to it in terms of vibe). The issue would be an extreme advantage for the first player, especially when you can win in 2-3 hits. So it would probably require longer battles to compensate for that advantage.
2) Make it phase-based but with a bit more flexibility in each phase, and remove turn-order for all but mirrors. In the move phase, you both set move simultaneously (not seeing the other player's move) and then you both move, not in turn order. And then you both adjust the angle of the lasers and hit fire and fire simultaneously. This was the initial plan, but we didn't have time to make a simultaneous move execution and laser rotations :) So we had to add a coin flip just not to make it a too-easy-win :)