Portal: The Flash Version MapPack

Portal: The Flash Version MapPack is a set of downloadable maps, inspired by Portal: Flash Version. These maps are compatible with Portal, and have been incorporated in the official Xbox Live Arcade version of Portal, Portal: Still Alive, as well as the Nintendo Switch version of Portal included in the Portal: Companion Collection bundle, under the Bonus maps section. The trailer for Portal: The Flash Version MapPack can be found here.

It involves the story of an un-named protagonist who wakes up in a Relaxation Vault. The player must make it through several test chambers, occasionally going off track to discover more parts of the facility, mostly trough vents.