Thanks for all the feedback! We are still taking notes on how to improve overall gameplay feel, as well as adding some QoL features that are very much needed in this state of the game. The boss' background is the actual timer! We know it's not very intuitive and a bunch of people suggested making it more noticeable so it's probably not a bad idea to re-think some core aspects about the game. On top of that, we also plan on doing some rebalancing since, as you said, there is a clear meta on which upgrades to choose and we'd like to make it more of a personal choice. There's still a lot of work to do and we're happy that you and many other people enjoy our game!