From Sonic Retro
The Cliffhanger Flip is a move performed by Sonic the Hedgehog exclusively in Sonic the Hedgehog Spinball.
The Cliffhanger Flip is performed whenever Sonic comes within vicinity of a platform's ledge, in which case he will automatically grab the ledge and flip up onto solid ground. This is a very useful technique that can be used to grab ledges that are either out of reach or to avoid falling into a fatal hazard. However, the move can only be performed on flat ledges - Sonic will not be able to grab uneven surfaces, such as a flipper.
If the ledge in question is from a moving platform, such as in The Machine, the platform will stop moving during the move's animation.
|“||Sonic will automatically grab ledges and flip up onto a safe surface to prevent fatal falls or avoid the jaws of Robotnik's monsters.||„|
— Sonic Spinball US manual
|Sonic the Hedgehog Spinball (16-bit)|