At the moment theres nothing much. Really its just press space to spawn a unit, then move your mouse around, the unit should be able to sense if your mouse is in a spot it can shoot.
Please make sure to give me feedback for what you want to see with this game and any bugs you find! Credits, really all of them are in the original Trench Warfare, I'm really just reusing assets (sound only) or getting them from the same source!