We couldn't open the video, so this is on the concept only.
Hold to dive while the terrain does the rest is the Tiny Wings loop. That loop has real depth because the timing of each release against each slope decides whether you gain speed or lose it. If your hills reward a well timed release and punish an early one, one button is plenty.
The pickups could add a second layer. Put some on the fast, risky low line and some on the safer high one, and the player picks a route on every hill.
On the theme, a cute poop will be a hook for some players and a skip for others. The icon and the first screenshot carry a lot of weight, so showing the sewer and the cleaning goal up front should pull in the curious ones.