You are a mighty Barbarian fighting against monsters, leveling up by slaying them. The monsters have HP and damage power equal to their level (1 to 5). When you meet one, you hit first, inflicting damage equal to your level, but if they are not dead, they will fight back. The cells with numbers indicate the sum of the levels of all the nearby monsters that touch the cell. Press the 1 to 5 keys to mark a cell with a green number. Press space to erase the number.
I want to make a roguelike version of this game but I don't know how the systems or anything with the pen tool or lists or custom blocks work. So instead I just did a little recolor.