Time Warp Plate

Time Warp Plates (タイムワーププレート), also called Past and Future Signposts, are types of signposts that allow the player to transport to the past or future. These plates are only seen at the Little Planet and are featured in Sonic the Hedgehog CD.

Description
Time Warp Plates are slightly smaller versions of signposts, that are colored yellow, grey, and black. The sign reads either "Past" or "Future" with yellow font. Running past the Time Warp Plate makes the signpost flip once while a voice states the particular signpost's name at the same time. The symbol of signpost can be seen at the left hand corner next to Lives hud after moving past through time warp plate.

As the player runs past the signpost, the player must build enough momentum to break the sound barrier, and warp in time while the symbol of signpost starts flashing at the left hand corner. When the player gains enough speed, the screen flashes and transports the player to another time. If the player fails to build enough speed, the symbol disappears and the player must find another Time Warp Plate and try again. It will also disappear if the player runs past the Goal Signpost before the Bonus Plate. When the player is transported to the past or future, the player's life icon is replaced with a P or F icon, representing Past and Future, respectively.

Time Warp Plates are first seen in the second zones of each stage. In present time, both past and future signs exist and are available to use. However, if the player is in the past or future, only one type of sign will exist. The player can either travel to the bad future (if the player hasn't destroyed the all the Roboticizers in the past or hasn't collected all the Time Stones), or the good future, if the player has collected all Time Stones from the Special Stages or destroyed all the Roboticizers in the past. However, if the player has destroyed all the Roboticizers, the player will automatically transport to the third Zone's stage in that level with the good future (or the bad future if the player hasn't gotten the Robot Generator from either of the first two stages) where Time Warp Plates are not featured.

Trivia
Sonic Super Special Magazines by Archie Comics.
 * The Time Warp Plate with a past symbol is seen at "The Mobius Timeline" feature, which has been part of the