By typing "real speedrun mode" into the cheat box, you will get an ingame timer, and that should be used for timing this game.
The main movement is gliding(holding spacebar) ,
at first turn right and jump/glide over the hills,try to hit one of the "boosters" to glide you up.
2 places for landing: on the big white roof,and jump down, or go to the smaller "roof" on the right and jump from there,
On the right there should be a fenced off room, jump over the fence and start mashing space to get up the "elevator", you should be at the end of the level,then just glide towards the end, you will also usually get a considerable boost out, but it might be a little too left/too right so you'll
miss the staircase.
When flying towards the coffin, go at a high speed and try to land on the edge of the trigger. This will shorten the cutscene considerably.
Coffin glitch is a frame perfect cutscene speed up which shortens the cutscene time to 16 seconds as opposed to 23-29 seconds. This is achieved by landing on the same frame and at high speed on the edge of the cutscene trigger.
Try to swing off the slide, just roll between the sides and you will fly off
near the beginning when there is a lower portion of the slide.
Glide left, there should be a pillar on the left where you can boost off of. Then glide towards redemption and stop gliding at the end to jump down quicker.
You can start moving before the camera goes normal, but this almost always costs time for me.
When you are at the ending part,press "s" and glide backwards during when the camera is locked at a single point. Then start to destroy the area around the "A R T" .