These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Good Bad Bug: If, on the last level on episode 1 or 2 (so, level 10 or 20), you have one or more magic items active (the potions and cloaks), they will remain active in the next episode seemingly forever (at least until you die). Here's how this works:
The game timer keeps track of how long you've been in the entire episode (this part you don't see) as well as in each level. When you get a potion or cloak, the game calculates when it should expire (giving 40 seconds for either potion, 28 seconds for the gray cloak, and 18 seconds for a blue cloak; collect more than one, and they stack). When you complete an episode, the overall game timer resets to zero, but the game doesn't recalculate when the items should expire. So, if you took, say, 45 minutes to complete the first episode, and you had a gray cloak active at the time you did so, you will get 45 minutes (plus any remaining unused time) of invincibility to start the second episode.