Supply fills up by itself. Tap a card (or press 1–9) to send that soldier to your front line.
When eight soldiers are at the front they charge the next line. Press Charge! (or Space) to go sooner.
A line is yours when no Tan soldier is left in it. Take the line by Tan's fort to win.
Hit soldiers tip over and pop away. Medics stand them back up if they get there in time.
Gadgets (Q, E, R): the marble bowls down a lane, the paper plane drops water balloons, the wind-up mouse draws their fire. Tap the field first to pick the lane (and the plane's spot).
Win battles for tokens and spend them at the Quartermaster: tougher soldiers, more supply, bigger squads.
Drag to look along the field. Two fingers (or the right mouse button, or [ and ]) turn the camera; pinch, ctrl+scroll or - and = zoom; C puts it back.
Machine gunners and snipers stay in the line and don't charge.