-The controls for each game should be mentioned at the start of each minigame, along with the objective if it's not already obvious. Though they are mentioned in the author comments, it's hard to memorize and inconvenient/tough having to scroll down and find them while in the midst of a minigame. Even after reading the controls, some of the minigames are still a little unclear in what you have to do (more on that later).
-Difficulties/Rewards: I get that you want to reward the player for playing/beating Stiffy difficulty, but that doesn't mean that it has to be the only difficulty with any nudity (especially considering how difficult Stiffy is, more on that later)! At least it's good that on Sexy difficulty there's stripping down to the underwear. However as an alternative you could have full stripping on every difficulty (or at least for Sexy), but have additional rewards for beating higher difficulties. That Vortex minigame you unlock for beating any difficulty could instead only be unlocked for beating Stiffy.
-A loss of a life/crystal should NOT result in losing points as long as the player is able to complete the minigame before losing all 3. OR you should have the option of giving up/not retrying a minigame after losing a crystal, in order to save yourself from losing more points. With how it works now the crystals are more like a counter for the amount of times you can lose points on a minigame rather than lives. But without that option, then instead of losing 40 points per crystal lost, you should lose 120 points only if all crystals are lost. Otherwise no point loss and gain the full 100 points for beating the game. It's hard enough to rack up points as it is, especially because you can randomly lose points and often more than you can randomly gain. Losing 100+ points randomly really sucks.
-For the questions you don't have to reveal the right answer, but the player should at least know whether their choice was correct or incorrect. Out of fairness yes but also to help confirm the integrity of the game, or in other words so that players can more easily tell if a question is inaccurate or bugged. It's possible to tell anyway if you memorize the position of your point bar before the question and seeing if it went up or down, but you shouldn't have to go through that trouble to tell. Random trivia is painful enough at it is, so the player should at least be given that benefit. Also there's barely/not enough time to read and answer questions on Stiffy (certainly not 20 seconds like the directions say, which not even Easy gives).
Game Specific/Stiffy Difficulty Issues:
-In Cutter if you move too fast it doesn't cut the grass. Also there's barely/not enough time to complete it on Stiffy.
-In Memory you can't undo a bad choice so if you mess up just once, you fail. Anyway if it was truly a memory game, you'd be able to cycle through the choices at your leisure rather than having to time it too. Also there's barely/not enough time to complete it on Stiffy.
-If you mess up just once on Circuit there's not enough remaining time to complete it on Stiffy.
-In Dodge it was not explained well that you had to either jump OR duck and it's hard to tell in time.
-In Catch you should be able to use the mouse instead of the arrow keys. It'd feel way more natural.
-In Jumper the rope can start too close before you have time to react/jump.
-For Grab it's a little unclear that you need to press space when the object is between the white lines.
-Evade is virtually impossible to complete on Stiffy and too long. I even think it's too tough on Sexy. Was it even playtested properly?
-In Boat the barrels can be in positions nearly impossible to dodge and it's hard to tell if you have enough space to squeeze between them or on the sides. This is partially because the collision for the boat is bigger than it actually appears. Also it's too fast and long on Stiffy.
-In Balloon it's unclear that you have to inflate it to the same size as initially shown, there should've been a button to deflate it in case you inflate it too much, and it's too strict on Stiffy.
-In Rain the rain can linger under the umbrella after it is covering the guy which makes you lose. This makes it especially tough on Stiffy.
-In Aim it's just lame that the crosshair moves in circles and doesn't make much sense other than to screw with the player. It moves less on lower difficulties but it's pretty annoying on Stiffy.
Honestly though aside from the unclear controls/objectives, a lot of these issues wouldn't matter as much or even at all if Sexy was the highest difficulty rather than Stiffy. Then the Easy difficulty could be the new Sexy/Medium and you could have an even easier difficulty for Easy, or just have the 2 difficulties. To anyone hoping to see nudity in this game you might not want to bother wasting your time. But if so then good luck... you'll need it.