Oh! I beat it then. Because everything's automated and I had cranked through the whole skill tree, I wasn't actively watching the screen anymore, so by the time I saw the writeup (which, again, is a bit obscure as to whether the game is done) I had bled out (from the scaling automatic environmental damage I guess?) and recycled.
Yes, you beat it, both endings actually! The first one triggers when you buy the last node of the constellation (that's the credits screen), and the second one is at biome 106.
The death wasn't supposed to happen, though. When you reach the second ending, the Hollow is meant to stop running and the Rot's drain is meant to stop too, so he can finally rest there. Dying on the ending screen and getting recycled was definitely not how that moment was supposed to play out, sorry it ended that way for you! Your guess about the drain is right otherwise: it grows with distance, so by biome 106 it hits hard.
Fair point on the endings being too obscure about whether the game is over. That's a good lesson for my next project. Thanks for sticking with it all the way, you might be the first player to see everything HollowRun has!
Your suggestions make total sense, and I actually had the fixes ready: the clearer constellation ending, and the Hollow stopping at the Rot's source. Unfortunately, I found out that because of how itch hosts browser games, uploading a new build would wipe everyone's saves, including yours. I'd rather not do that to anyone who's put hours into the constellation, so I'm holding off on the update for now.
So, for the record, here's what the endings were meant to say: completing the constellation is the first ending, but not the last. The second one is at the source of the Rot, at biome 106, where the Hollow is supposed to stop and finally rest. You reached both, which makes you the first player I know of to see everything HollowRun has.
Lesson learned for my next game: set up saves that survive updates from day one. Thanks again for playing all the way through and for all the thoughtful feedback!
Update: I found a way around the save problem! The new build now picks up your old save automatically, so nothing gets lost. Your suggestions are in: the Hollow now stops at the Rot's source, and the constellation ending is clearer. Full details here: https://zer0fast.itch.io/hollowrun/devlog/1668881/update-11-your-biome-is-saved-...
Thanks again, this update exists because of your feedback.
