If you have some ideas

Mode without using skates? Example:

%Survive without skates: (15min aprox)

Mode with keys, like a Mystery box 1, 3 and 5 or only 1 and 3.

Subway Surfers Key:

19s 497ms

50.000 Coins speedrun?

Longest time off the ground. So you can be on anything but the bottom floor. And your run can start at any point in your run but once you hit the ground the time is over. This could have a hoverboards and no hoverboard subcategory as well.