Thinking with Time Machine

Thinking with Time Machine is a Portal 2 modification featuring a new gameplay element known as the "Time Machine" which allows the player to record and play back their actions in the game world.

Time Machine
Accurately recreates the player's actions. Activated by hitting the (default) key, then the  key to stop. The key activates the mechanic and enable the Machine to start replicating the actions. Is a clipboard in Chell's left hand with a screen showing what the time-double sees, or an Aperture logo showing which mode the time machine is set to.

Anti-gravity buttons
These are first introduced in Test Chamber 5. They come in the form of regular buttons (Sphere, Cube, etc) on the ceiling. By letting go of a Cube or Sphere close to it it will slowly move towards it and finally activate the button. These only appear once and for people playing the game for the first time will have trouble with it due to lack of information on how the buttons work.

Extensive use of Laser Fields
Later test chambers involve complex Laser Field activation puzzles.

New textures for Cubes, Buttons
Cubes have a spinning Aperture Science logo in the center. Droppers assemble the cube from pieces inside the dropper. Exit doors are see-through and elevator rooms are differently made.

Glitches

 * Frankenturret assembly glitch
 * A glitch occurs when making maps using TWTM's in-game PeTi. Because there is no model nor animation for assembling Frankenturrets, when a Frankenturret is assembled its model is replaced by an Edgeless Safety Cube and a Weighted Storage Cube. When the animation is complete the Frankenturret doesn't spawn.