For example, "top-right to 01" means if you enter the door in the upper-right quadrant of the level you'll proceed to Field 01. There are usually many doors in each Field, so there will often be multiple entries here.
If it had instead said "top-right to 18/28" it means "normally, you'll go to 18, but sometimes you'll go to 28". The second Field is always an Ending Field.
Which Field you go to depends on your total play time. If you've played for more than 30 minutes you'll go to the second Field listed. This is the 30 minute rule.
What kind of strange objects you'll find in the background.
Also, whether small birds and fish wandering around.
What traps or machines exist to help or hinder Umihara-san.
The type and quantity of enemies.
Randomly spawning enemies.
How many backpacks (1-ups) are on the Field.
If the time in a stage reaches zero, you lose a life.
A scaled-down map of the level.
Shows locations of enemy spawn points, enemy paths, trap locations, backpack locations, and door locations.
The best way to get to each Door, and how hard to expect it to be.
Expect demonstration videos of each.
The fastest times to each door.
Tool-assisted and non-assisted runs will be kept separate.