No Way In

Used tricks: Star Pass
https://mekoramaforum.com/threads/star-pass.1402/
Other tricks: low ceilings, SSS, R out map, and a trick that makes B freeze on stairs.

There is also an R drill hole structure from @XSHY .

There are two stars used to activate the mechanism, and the natural trigger of the push ball does not need to be deliberately searched.
In fact, the part other than the Star Pass should not be too difficult, but it is indeed not easy to find the way. Please combine the video to complete the level.
The last step is still a bit interesting. Do you want to know how to get the stars in the room?

Spoiler: Video

To get to the slider, I know R has to climb onto B's back, but I don't know how. So I won with B.

I got a star attached to win mechanism with R. But this is quite risky because R could fall from B on the way.

+ I like R crawling in the tunnel

Excellent!

Great finish especially as I wasn’t sure what to expect. Took a while to see how to get R to the finish and i presumed my way was a shortcut but on looking at the video i find it is similar although i dropped R and then walked B round to unfreeze R. Unfortunately never saw R crawling so it was good to see it in the video rather than having to restart.

Unbelievable creation with so many incredible moves and mechanisms! Totally needed help from the vs so thank you for including that amazing ending and really enjoyed Righty's tunnel trip