Baba Is You - the TEMPORAL levelpack. In this pack, objects can be colored green (past) or purple (future), and there's also a clock that is a timeline switcher - if an object goes into the clock it destroys that object and switches to the other 'timeline' (in the past green is real and purple is not; in the future purple is real and green is not).
Download: mega.nz/file/UvcD0DTS#R75IwGL...
It also has PAST and FUTURE as lonely-style-prefixes as well as X IS TEMPORAL which (as long as X IS TEMPORAL is active) turns that object into a non-past non-future version of it.
This pack (like some others) has a tenuous connection to actually being about time (since past vs. future is interchangeable). the last level also does not seem to work completely properly and there is a very likely cheese that ignores the top-right of the level because for some reason you can interact with 'past' things. it also seemed inconsistent at some points (there is one level which is a remix of a previous level where a green rock can't activate the clock, when in the original level it could, and I don't think there was a rule about rock).
I enjoyed the vibes of playing with this portal-reloaded-esque mechanic though. :)
Playlist (CUSTOMS): • Baba Is You - Customs ...
"secret" discord: / discord