Kill every mob as fast as possible.
I also highly recommend you check out SwaagDudezz's ideas in the forums as well because Minecraft: Java Edition Category Extension should have much more to it, as it is Minecraft after all.
Are DLC for the deliveries allowed? It doesn't specify in the rules.
It would be a very interesting feature to see speedruns on certain levels like Jumpin' in the Dump, Flowers Bugs and Bugs, Sesame Street, Foggy Grouchland and most importantly Huxley's Chopper.
I was reading through the rules and I was greatly misinformed that difficulty does not make a change in gameplay and it does make a very big change.
In the level "Journey to Grouchland" it takes a whopping ~1:40 minutes to complete it alone in Easy, if you count the first level with it you're already on ~2:00
On Hard it takes ~52 seconds to complete "Journey to Grouchland" which is a ~48 second difference and that's just such an incredible change when the rules clearly say that there's no change in gameplay.
Thank you for taking the time to read this, mods update the rules and add a Hard% and Easy%?
EDIT: This also goes for Mine Games and a huge possibility for other levels too.
Much appreciated got VBA and the colors look horrendous, prob doing something wrong since your run looked so PEANUT BUTTERY
Want to speedrun this, what is the go to Gameboy Color emulator?