It took us quite some time and required a lot of patience and creativity. The most terrifying place was,
Zenon believes, Flying Battery Zone Act 2.
It might look pretty simple with those speed boosters and all, however there are two paths which we thought for a long time to be impossible to clear. But in the end we scrumbled just enough momentum to finally pass these places.
Overall it was not hard, since we got very lucky to find different ways to get through a lot of places. I happened to come up with a great move which helps gain speed when Knuckles tries to glide when he is about to reach the ground.
We also found that it is thankfully possible to push the blocks and the levers which open doors in Sandapolis with just landing on the ground after gliding.
But the two most huge advances of choosing Knuckles for such a challenge are that it's actually possible to move at all with him using only a jump button and the other one is about him being able to turn from right to left and the other way around due to sticking to walls and jumping off of them.
Knuckles is also able to gain speed on the curves after gliding to the right. Although somehow the left-positioned curves work just like the first ones. And that doesn't mean that they make Knuckles gain speed to pass further to the left - instead they make him go back to the right with a lot of speed. Sometimes it could be used to help go back somewhere easily, but the other times it just didn't let us proceed further to the left if we needed.