It's interesting how adding a % chance of failure really changes the dynamic of the clicker game! I had a couple of unfortunate false starts (failing on the first or second click), but once I had enough CPS the game became pretty easy to win. I found if I left 2-3 upgrades, I could pretty much always get the doom flower and doom reducing seed to guarantee my survival. I think adding more endgame mechanics (or a prestige system?) would help keep it feeling fresh for longer. As it is now, I think the current game length is perfect.