yes there is. I found it.
Either that or I broke the universe but I passed the last puzzle by running through, not floating. I was taken to another puzzle. I quit that puzzle and got some juice and when i fired up the game again, i was back at the 'official' last puzzle again. At which point i floated through and it ended.
There is an alternate ending. And i'm pissed that i started to discover it and it didn't save that progress. I haven't found it again. But that it's there? Yes because i started playing it. YOU just haven't found it yet previous answerer. There is also an alternate series of levels. Everybody's found or knows about those. I haven't played them yet but a lot of people have (these people include many youtubers)