Thanks for the helpful feedback. Yes it can definitely be difficult to figure out when you're being attacked, I'm thinking about adding some sounds and particle effects when bullets strike the mech, as well as damage indicators on the HUD to let you know the direction.
Thanks for letting me know about the right click aiming, I'm a little torn now but I think I'm starting to get a plan for how I can get the best of both worlds. Rather than a click and hold to aim I'm thinking of a click to toggle meaning that you don't need to hold the button for long periods of time. Then I'm thinking to have the zoom controlled separately. Either way I think it needs a bit more play testing to find the right balance.