Irrational Number Line Games, LLC
Moongha Invaders Boardgame Miniatures
Here are some plain plastic minis that go with a game called Moongha Invaders. They're roughly 28mm scale, and it's a big batch of minis for the price. The game has two-player battle rules (survivors vs monsters) and multi-player rules (monsters v monsters v monsters v monsters).
Here is a set of them painted up.
These are the survivors for the two players game. There are also eight generic "army men" for the multiplayer game.
And the monsters. The game comes with four sets of these in red, yellow, green, and blue. So with your painting, you can come up with a color scheme to tell the teams apart in the multi-player game.