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.
YMMV: Zelda Classic
Demonic Spiders: Besides the original game enemies, you've got worse versions of Darknuts, Wizzrobes, and Octoroks to possibly contend with.
With the enemy editor, it's possible to create your own Demonic Spider.
Good Bad Bugs: There have been several bugs that benefited the player over the course of the program's lifespan.
Growing the Beard: As the program aged, it added items and elements found in other Zelda games, most of which were met with positive reception. It also squashed some serious game-breaking bugs.
That One Boss: Level 6 of the Fourth Quest has you fight a Giant Moldorm with forty segments. It takes up most of the screen and the fight can take forever. If the player dies, he or she will have to fight the boss again with the segments restored.