This is fun! Always think tower defense is a stale genre, and it's always a blast when people try to do it with a different light. Combining auto auto-clicker with a tower defense is certainly a nice idea, and I can see how that may evolve. Nice work on that! The graphics are super nice. Very cute cats too. The gameplay is satisfying and quite balanced, though after getting the hang of the game and how the upgrade works, it becomes much easier than I should be. Also, what on earth even is fortday XD that's hilarious. I like this game a lot.
For some criticism, I'd say being able to put only a few cats (towers) on the board really undermines the free-building tower defence game's potential a lot. It's that type of game where you build a long labyrinth that forces enemies to go through, and I really miss that fun. I would think there is a missed opportunity of placing the upgrades directly on the board. Also, a few more cats would be nice too, mining cats, clicking cats etc you get the idea. Other than that, the game was pretty polished, and I don't think there is much to criticise. Well done!