Time Warp signs are tall, thin posts that resemble Star Posts in some ways. They have a yellow post in their bottom part, a long, grey rod, and a black sign in their tops that can say either "Past" or "Future" in a yellow, cartoonish font. In Sonic Mania, they feature a grey, hourglass-shaped post with a black center with a white star in it in the center of the yellow post.
Features and abilities
Time Warp signs allow their users to enter the Time Warp, a phenomenon which allows the user to travel through time through the use of speed.
Sonic the Hedgehog CD
In Sonic the Hedgehog CD, Time Warp signs appear in Zones 1 and 2 of every Round, as unique features in the game. They come in two variants: the "Past" Time Warp sign and the "Future" Time Warp sign.
In gameplay, running past a Time Warp sign makes its signpost flip once while a voice states its particular name at the same time. Afterwards, the player must build enough momentum while the signpost's HUD symbol flashes. When they begin gaining speed, the playable character will have white stars trailing in their wake and screen begins flashing. If the playable character can then keep up their speed for a few seconds, they will enter the Time Warp. If the player fails to build enough speed however, the symbol disappears and the player must try again at another Time Warp sign. 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.
In the present time, both past and future Time Warp signs appear and are available to use. However, if the player is in the past or the future, only one type of sign will appear. If the player uses a "Future" Time Warp sign in the present, and they have not destroyed the robot teleporter in the past or has not collected all the Time Stones, the signpost will take them to the bad future. Otherwise, it will take them to the good future.