Rolling into the side of one of the small purple, bouncy mushrooms in Pipe Towers Zone puts you into a semi-permanent half-grounded, half-jumping state.
Rolling or spindashing, not jumping, into the side of the mushroom initiates the bug. While in this state, you have free control over your movement and damage enemies on touch. You can exit the state at-will by pressing jump, which plays the jump sound but immediately uncurls you onto the ground.
You can charge and release a spindash, which seems to behave normally. However, charging the spindash doesn't lock you in place as it normally would, and moving around will end the spindash. In either of these cases, when you come to a stop you will appear to uncurl (unless you hit a mushroom again while rolling around), but this is only a visual change - the bug is still active, and you will still damage enemies on contact.
Video of the bug in action:
https://www.youtube.com/watch?v=25tC5PUdavE
(The number 1 being a white square is unrelated, fsr SRB2 and OBS really don't get along.)
Rolling or spindashing, not jumping, into the side of the mushroom initiates the bug. While in this state, you have free control over your movement and damage enemies on touch. You can exit the state at-will by pressing jump, which plays the jump sound but immediately uncurls you onto the ground.
You can charge and release a spindash, which seems to behave normally. However, charging the spindash doesn't lock you in place as it normally would, and moving around will end the spindash. In either of these cases, when you come to a stop you will appear to uncurl (unless you hit a mushroom again while rolling around), but this is only a visual change - the bug is still active, and you will still damage enemies on contact.
Video of the bug in action:
https://www.youtube.com/watch?v=25tC5PUdavE
(The number 1 being a white square is unrelated, fsr SRB2 and OBS really don't get along.)