Artillery Duel 236M
the author of this app says:
Commodore-64 owners will long remember the C-64 classic, Artillery Duel. Well, now you can play it on your PalmOS device! Supporting grayscale or color, this early port of the game takes you to the battle field where war is raging.
Gameplay is simple and the graphics reasonable. Although this is a clone, the author has clearly kept it close to the original.
Supports greyscale and color PalmOS devices.