Untitled 3D Platformer (U3P) was a school project for a computer graphics course made in a couple weeks. Gameplay is inspired by Fez, where you can move in a single 2D plane, but rotate the camera into an orthogonal plane. Additionally the camera can be rotated to change the direction of gravity. There is also minimal combat to provide some friction while moving.
There were four levels made. The first is based on Super Mario World 1-1 to show how the mechanics apply to a 2D world.
The second level is inspired by the classic Pipe Screensaver. Here the full capabilities of the 3D controls can be seen and tested.
The third level is a bit more exploratory. Larger structures float in space, and it is technically possible to manipulate the camera and fly directly to the exit.
The final level is a randomly generated heightmap using I think Diamond and a single lava layer placed at one point. The level is pre-generated and selected based on how nice it was to navigate. The level is also unique as the four enemies must be defeated before the exit will unlock. An interesting game mode exists where the camera plane is parallel to the ground and combat becomes like a gravity shooter.
Distributables can be found here while the source code can be found here.