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.
Anti-Climax Boss: In the first game, Risky's Tinkerbats have apparently forgotten to install weapons and defenses to her All-Purpose Steam Powered Tinker Tank, leading to a "steam-powered behemoth" that could only damage you if you jump on its threads or stand in front of its two external steam vents.
This is more than made up for by Risky Boots herself.
Generally, any game with a Virt soundtrack is guaranteed about nine separate instances of this trope.
Special mention should go to "Burning Town". Like others, it came back in Risky's Revenge, but the remix (available at the composer's site) takes it Up to Eleven, dipping into the GBC version at times just for extra impact.
Through the Trees combines this with one of the lushest, most visually stunning levels in the game.
Cult Classic: The first game bombed on release and the sequel spent years in Development Hell because publishers didn't want anything from WayForward that wasn't a licensed game or a casual downloadable title, but still manages to have a sizable fanbase most other smaller games could only dream of.
Demonic Spiders: Compared to everything else, the skeletons in Risky's Revenge. They're fast, do more damage than anything else in the game, have plenty of health, and can reanimate after death if you don't switch to elephant form and smash their gravestones.
Any enemy in the GBC game, especially the scorpion and mermaid women.
Game Breaker: Fighting the final boss as plain ol' Shantae? A nightmare. However, if you bring a full stock of Pike Balls and Fireballs, and/or use the Spider Venom, you'll be laughing all the way to the end credits.
And then there's this piece of fanart, released in hopes of encouraging WayForward to get hopping on the worldwide release of Risky's Revenge.
Moe: Cited by Destructoid in their review of Risky's Revenge: Your first instinct on seeing the female main cast is probably not so much "Whoa, that's hot" as "Aww, that's cute".
That doesn't stop the fanbase's artistic views, however.
Sophomore Slump/Even Better Sequel: Risky's Revenge has better controls, better difficulty curve, and superb graphics, but barely half as much actual content as the first game.
Squick: Rottytops, a (cute) female zombie, manages to break into a ruin — in order to allow Shantae access — by tearing her leg off at the knee and picking the lock with her exposed shin bone. (She puts it back on, though.) Still cute, but rather disturbing.
In a conversation with Bolo (Had while you are searching for the Zombie Caravan), he asks you to tell him if you meet any cute zombie girls. That's right, Bolo is a not-so-closeted necrophile.
How Uncle Mimic explains how he prevented triggering a pressure trap: by switching the treasure with the contents of his bowels.