Hi. Thanks for the feedback. I always appreciate some. I agree it is missing visual feedback on many things (money gain and tower upgrades for example). Def something I need to pay more attention to as it affect game play more than I thought it would. Sounds like such a rookie mistake to make haha but hey you learn from it right?
As for the control, it was designed on mobile first and the first tap was used to open up the tooltip and the second one was to confirm the action. I think on the desktop version it should be okay to have a mouse over for tooltip and a single click action. Something I will add in future updates. Thanks for the heads up.
I can take a look at your game for sure. I love doing UI so maybe I can help with it if you would like.