itch.io

Sorry but the game was built from the ground up for mouse and keyboard :<

You can hold the alt key for rmb, as I did, but you need to hold alt and the trackpad, and you actually swipe to shoot, but it relocates your aim. I can't get past the second level on the demo because you can't see your aim unless you're aiming, and you swipe to shoot, so you can't change your aim while aiming... it's hard but possible, if you're really good.

I have a touchpad too, I held 's' and then used the touchpad to move the aiming button.  I then just clicked and it shot the bullet.