New Styles:

Refurbished Style:

This style is a hybrid Old Aperture/Clean style. It uses an old enrichment sphere which has been upgraded by GlaDOS. Vactubes fill the area above the sphere, and all items invented after 1950 (other than gel and paint fizzlers) use the fully modern versions. Cameras are dotted around the sphere. Modern items are mounted on small sections of clean wall, sticking into the chamber slightly. Panel or piston related items use modern panels/pistons, attached to old walls or grating. Items that were in the original underground maps (like Flip Panels, normal floor buttons, emancipation fields) appear identical to 1950s versions. Some pre-recorded Cave voices are present, with GLaDOS introducing new items or commenting on Cave's remarks.
This is based off of the 1950s style by Carl Kenner.

Overgrown Style:

Destroyed and wrecked Aperture, like the first few levels of singleplayer. Features the Announcer, lots of plants and many broken test elements. Items will often have extra properties, so you can turn off certain types of damage if it may affect the puzzle (damaged portal surfaces, objects in different orientations, etc).

• Some items have an additional auto-rotate property, so for things like gel droppers or piston platforms on walls you may need to move them onto the floor and back to the wall to ensure plants hang downwards.
• If you find the flickering Observation room lights to be annoying, disable them in the properties of the Large Observation Room.

1980s Open style:

A version of the 1980s style but with a new enrichment sphere instance. The sphere is heavily damaged, showing the Test Shaft it is mounted in. Modern elements will add generators for that element to the test shaft. The map takes much longer to compile when this style is used, unfortunately.

Unlocked Clean Style

A special style which allows you to add/delete the mandatory items (exit/entry doors, the primary observation room). It could cause crashes or other bugs, be careful. Switching back to another style will preserve the changes. Don't try changing the game type (Coop/Singleplayer) without an entry and exit door, this can cause crashes when the game tries to swap which door type is visible.