les moitiers d'allonne
Here is a two players variant made by my 6 y.o. son and tested by my 10 y.o. daughter. You will need soldiers (8 is a good start, put them in the corner squares, two in each).
Each player alternate turns, at your turn you roll two dice, one is for your monster, the other is for tiny soldiers : the army.
A monster with soldiers in the same square is "distracted", he can do nothing but eliminate one soldier : if it wants to move, it can't, if it use a die so that it can't move, it eliminates one soldier.
Soldiers can always move, they gather if they move in a square with other soldiers.
Each monster keep the soldiers it eliminates. He can spend 3 of them to make an energy ray attack (this attack destroys a cube in an adjacent square, remember, in this game, orthogonal only is adjacent), it has to use a die so that it can't move to make this attack.
Last : with this variant, you can play with 2 or 3 cubes per square. My kids play with 1, 2 and 3 points cubes (short, medium and long colored wood cubes), they put 3 cubes in each square for a long game, and add 1 point bonus for every 3 soldiers at the end of the game.
I must say, having my kids making game variants makes me very proud :)