Farmageddon by Joel Davis 2017-05-04T06:24:08Z
@occultone, thanks! It supports single player against the CPU, (that's the default when you start it), choose "Human" for one team (that's you) and "AI" for other. The AI opponent pretty much aims at random but it should be playable.
Maybe it's a little confusing, each "team" is one player, e.g. all the Green cannons are the same person.