Also see, Reverse Mudslide: https://www.speedrun.com/webbed/guide/guxbz

It is possible to get past the metal door blocking the bottom of the mudslide area, without ever visiting the dung beetle path. This skips the need to do the beginning of the Dung Beetle path, saving around 1 minute (around 30 seconds faster than normal Reverse Mudslide).

First, enter the ant hill normally and complete the mech ant. Afterwards, return to the Power room and fling up to the gear area. Then, using a right-web fling + shooting lasers down to boost yourself, fling yourself up into the mudslide area, except when you're entering the loading zone, open your journal just as you're entering the mudslide. If you time it properly, the background should still be showing the ant hill area, but you should hear the dung beetle area music. Alternatively, you can also tell by looking at which dot on the map you're currently on. After 1-2 seconds, close the journal and you should be on the other side of the metal door.

If you're too early, you'll still be on the ant area screen with the ant area music, and you'll still be on the power-room dot on the map. If you have journal mapped to two separate keys, you can quickly flick both of them to close and re-open the journal, to try and advance 1 frame forward.

If you're too late, one of several things can happen.

1. The journal doesn't open
2. The screen starts to move upwards slightly, but stops (with some slight screen tear at the top), along with the dung beetle music playing.