Ok These will be in no particular order and may not work as a gimmick for a full level Maybe a short one like your Donuts or your Loafs Feel free to put your own level Gimmicks for yru'oe levels in the replies and give your thoughts about these Level Gimmicks

1 - Dives can be redirected by going into a slope or a corner or stuff like that this was used in hit level Aggregate of Strenuousness Where you have to dive into corners to redirect your dive as to not Die

2 - You keep all of your jumps if you fall onto a wall, Even single jumps, your able to single jump into the air if you go off a wall whilst having fallen off it, this can create for sections where your forced to not walljump or have to do a very tight jump involving using a wall to stall for horizontal momentum this also can be combined with Hit utilized Bug triple jumps to use a triple jump off a wall

3 - Ok this one might be false but i think Speed panel effects stack ontop of eachother but the most recent one is what speed you will have, You could maybe use this for a puzzle level where you have to choose which speed you need to have for portions and route out a order of speed panels

4 - Controversial one but You are unable to do biiwa while having a speed below like 14 (Speedpanel numbers wise) so with the previous one you can make a level where you have to attempt and dodge the floor so you can keep the biiwa state and use it to beat the level because you cant get into the biiwa state without enough speed

5 - Water currents

6 - Negative speed cobwebs

Cobwebs at negative speed cause all velocity you gain to be increased while your in the negative speed cobweb (Rolling increases it exponentially causing you to be sent into the end of the universe) and it is quite interesting, i wanted to make a level using this called Impetus gale but I dont know if i am going to Finish that Sorry Guys and Velvet Sorry Velvet Sorry Velvet

Healing panels
Have a lava block and in settings make the damage a negative. Higher number for faster healing

New one: Gravity Switch.
Have a strong spring and when you roll on it you will go to the celing (make it close and big!) and start rolling on it. You will fall off when you hit a wall or stop to a halt.
---------------------------------------------------------------------------------------------------------------------Invisible mode
(Mainly works with the setup above)
Roll into a cobweb with a big or so amount of sticky (or lower idk 0.5 sent me) and someway somehow by chance you will turn forever invisible... Not even a reset can save you...
-------------------------------------------------------------------------------------------------------------------Those are all I have so far.

invisible mode can be forced by putting a cobweb on the hidden statue block i think, though this resets yo to 0, 0 for some reason so im unsure

Invisible mode just needs a big cobweb stick.

it'll also most likely be patched in the foreseeable future, so i wouldnt rely on that (too late)