[2.2.13] Jumping or using Spin while on Rollout Rocks while inside Quicksand/Lava FOFs can lead to semi-softlocks or other oddities.
Normally on Rollout Rocks you can't use the spin key to perform actions but you are able to jump off them... however in an edge case if you're inside a Quicksand FOF or a Lava FOF while on a Rollout Rock... this can lead to a potential semi-softlock or other strange oddities. Here are some examples
-
Jumping while inside the FOFs will let you jump for a frame but you will be unable to jump off the rollout rock. If you jump within 1 frame BEFORE you exit out of the FOF... then you will get semi-softlocked and will be unable to jump off the rollout rock unless you re-enter those FOFs again and jump while inside them or if you somehow take damage in this state outside the FOFs. This can also lead to an exploit where for those that can damage enemies while jumping... they will remain in their spin frames and can damage enemies without any issue... unless... they can somehow damage you during this.
-
Spinning while inside them will let you perform a spindash if Sonic / Tails / Knuckles / Metal while Fang will fire his gun and Amy will perform her Hammer Attack... though not fully as it'll cancel itself due to going back on the rollout rock. In the case of spindashing this leads to an exploit where you will remain in your spin frames upon exiting while spindashing thus allowing you to be able to damage enemies... unless... they can somehow damage you during this.
Video:
Here's a test map to mess with which includes the Quicksand FOFs as well as a Lava Slope to mess with. The Jumping softlock prob can't be done inside Lava FOFs due to it teleporting you upwards if you jump while inside them however the Spin Key will work without any issue in this case. Lava FOFs are a bit weird anyway since you may get crushed while inside them.
Map: