Got the ending but didn't finish the game Xbox

[phizeal]

So I was flying around with my jetpack and I'm pretty sure I was able to get to the end area when I wasn't supposed to. I know there was at least one slime doors I hadn't opened, and I certainly didn't make the desert lush again entirely. But I got to the end area which I assume is some kind of portal where you make a decision (couldn't do it) and then when I doubled back, trying to get out, I couldn't. So I decided to emergency exit, and when I returned home the credits rolled. It brought me back to the game afterward but I am worried I missed something. I haven't looked up what the ending should be because I was hoping not to spoil anything (been playing this way throughout). Did I break the ending for my playthrough?

[Calydor]

The ending is about finding out what decision Hobson made; the game is still playable after to continue finding secrets, reviving the desert etc.

At the moment there's no decision to make for yourself.