The end is just when everything is visually maxed out. The middle streams make you bigger but shrink your cock and the outer one grows your cock. After your body doesn’t change anymore the stats can still go up, so you tank some points to your body and then synch only with with the outer one to grow your cock to max size. Then there’s the alien stat which goes up with everything, and it’s maxed when you start lactating and cumming black. The final message is just that you maxed everything out and it still doesn’t end the game, not missing anything important. Also might be a bug if it doesn’t work, didn’t have that much time to test everything.
So glad you liked it!