itch.io

To be honest, interest is quite weak. The mechanic is a nice idea, but it isn't obvious admittedly or easily understood at first glance - only perhaps to veteran TD players, but not a casual audience I suspect? Anyway, since interest caps out at +10, it doesn't scale well late game when each enemy already gives +7 each, and enemies come in huge quantities. Killing two enemies basically gets me the max interest lol. And at 5000 gold, whether my interest is +0 or +10, doesn't make or break endgame.

As for early game, just my opinion but I feel it's not worth saving up for that minor interest because the early game is where every tower and damage matters. In fact, as Admiral Ackbar says... IT'S A TRAP!! Saving up for that slight interest cost me lives, which is a permanent loss for the entire game with no way to recover from (unless you add % chance to lifesteal tower). I'd rather not have skimped on a tower if I could place it in early game.

So while an interest-ing (pun intended) mechanic, it falls short in execution. Removing the cap will make it interesting for endgame builds, but can easily lead to a broken mess if unbalanced. It also works better for games where the towers with higher costs that can scale much further.