trying to guess what the mechanics are
looks like clicking the yellow up arrow spends your gold and increases your growth number (but not enough to make it non-negative, in any of my attempts so far)
clicking the house then clicking somewhere on the map appears to place a small red circle that disappears shortly thereafter. I assume there is some way to make it not disappear, but haven't figured out what that is.
clicking the sword then clicking somewhere on the map creates a white circle, but only if you do it adjacent to one of the enemy colors. Presumably this attacks them, but I haven't observed that having an effect.
I think the number on the menu item refers to how much gold it costs. this number becomes infinity eventually, which is presumably game over. I have no idea what the right-arrow button does, but its cost keeps going up