Horse.
[parasitic bomb].
People complain about this all the time, and yet it's NEVER happened to me. Not in 4, not in Rush, NEVER. If you get what's in that video, I'm convinced YOU'RE doing something wrong.
Something similar happened to me 5 seconds into the demo, and all I did was try a homing attack. Speaking of the homing attack, I did one close to the first slope, it locked on to the fish robot, and then it sent me flying as if I had just done a fully charged spin attack. It was a funny surprise I guess.
The game does feel a bit off so far, and Sonic takes too long to speed up without a homing attack, but eh, I'm enjoying it I guess.