Beat the game to ending 1 and nothing was nsfw... gonna take too much time to get the other endings. I beat the boss on my last life with 1 hp...
The game saves your fastest time and highest score separately for each area.
This means you can do a fast run and make a beeline right to the exit and then do a slow run after to get every little thing on the map and the game will keep your fast time even if you went slower the second run.
Hope this helps!