A collection of compiled maps for HL2, EP1, EP2 and Portal, that "accidentally" ended up in the final version of the Android port.

Most of these maps were most likely used by the developers to test how well the game elements worked on the Andoid/Tegra platform.

Alongside devtest maps, the collection also contains early styleguides for the cave and forest environments for EP2, as well as a prototype of the final EP2 mission, where the player is required to refuel the helicopter in order to escape.