The Enrichment Center is required to remind that that there will be a lower-poly cake. Portal 64 is a spectacular demake of Portal for the Nintendo 64.
The work of James Lambert, it works wonderfully on the 27 year-old console, and Portal's clean industrial environments adapt well to an early 3D-era aesthetic that the 2007 original itself parodied.
The to-do list remains extensive, bugs and missing features are abundant, and installing it requires familiarity with linux-based N64 dev/emulation setups.
Portal is a classic subject of demakes. Check out this one, by Alex Marcolina, for the Ti-83 calculator.
(How about a remake for Apple Silicon, while we're at it?)