As too often happens to me, I want to see how many mercenaries I can buy, so I select the first mercenary camp in the list as that is the cheapest one.
What happens?
I click on the first hospital by mistake.
And spend 7 Billion on an upgrade from 45K to 60K

Gawd, I wish we could cancel a hospital upgrade !

If you want, create a feature request - there's a separate forum for that - but it probably won't get too many votes.

There are definitely times an undo would be nice across all WZ idle, not just hospitals, but it's hard to balance with quick gameplay and avoiding hacking, such as gaining a benefit, using it, then undoing. I guess an undo within 5 seconds would prevent hacking. But honestly once you do it once you learn to double check very quickly. Like learning to unclick the superpower button after finding out you wasted 4 extra powers.

Edited 9/5/2025 20:44:19