The Time Warp sign is an object that appears in the Sonic the Hedgehog series. It is a type of signpost found exclusively on Little Planet. An unique feature on the planet, Time Warp signs allow their users time travel to the Past, Present and Future of a Zone using speed.
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.
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 to break the sound barrier while the signpost's HUD symbol flashes. When they gain 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 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 present time, both Past and Future signs exist and are available to use. However, if the player is in the Past or the Future, only one type of sign will appear. If they use a "Future" Time Warp sign in the Present, and they have not destroyed the robot teleporter in the Past or have not collected all the Time Stones, the signpost will take them to the Bad Future. Otherwise, if the robot teleporter is destroyed, or all the Time Stones have been collected, it will take them to the Good Future.
In Sonic Mania, and its expansion Sonic Mania Plus, a "Future" Time Warp sign makes a cameo, with a slight redesign given to it. It is seen during Stardust Speedway Zone's transition from Act 1 to Act 2. In this game, Classic Sonic, Classic Tails and Classic Knuckles would use this Time Warp sign to travel from the Past to the Present of the Zone. Later, in Sonic Mania Plus' Encore Mode, the group, along with Mighty and Ray, would use another Time Warp sign in Stardust Speedway Zone to travel from the Past to the Present of the Zone again.