It really reduces the difficulty of the Challenges to know what each one requires. Instead of listing the requirements for each Challenge right next to them, you ought to instead put all the abilities needed off to the side, like in a box that says "Recommended Abilities". That way, you know which abilities are required for the stage's Challenges, but you'll still have to figure out which Challenges require which abilities.
I think the challenges should not have those icons indicating which powerups you need to complete them. Part of the challenge should involve the player puzzling it out themselves.
Warrior's Log, Day 13. It seems my fears were confirmed today that this was always meant to be a suicide mission. I had been delaying the inevitable by performing regular upgrades on my armor. The enemies keep getting stronger, but I am able to prevent their attacks from doing any serious damage, allowing me to win out through sheer endurance. Unfortunately, as I stepped into the first room of the day today, my Iteration counter at last malfunctioned. Before losing all power, it displayed 238. I still don't know what it means. Regardless, it was never meant to last this long. On top of that, my food rations have run dangerously low. I could sure go for that croissant right now.
It's not the amount of clicking that's the problem, but rather that all the buttons are badly sized. The least important ones on the bottom bar - Settings, Manual, Save - are the largest, while the most important ones - Go To Request, Fast Forward - are the smallest. That's the opposite of how it should be. You need to make the actions players do most often easier to find and easier to click.
The game doesn't seem to always respond to my mouse clicks. It's especially noticeable with the dropping frenzy; I think I'm not allowed to drop a new seed while one is still falling. But that would effectively mean that I am being penalized for not rapid-clicking with the right FREQUENCY. This mechanic definitely needs to be reworked.
I am now suddenly running into a problem where the framerate fluctuates wildly. One second it feels like molasses, and the next everything's speeding along. Needless to say this game relies entirely on a stable framerate to even be playable. Fix it ASAP.
Perhaps an Easy Mode, allowing up to three hits, would make this game approachable to a wider audience. Obviously, it should be made apparent on the episode select screen which ones you've completed on Easy, and which ones on Normal, so that the novices can still be distinguished from the aces. (I freely admit that I am a novice.)
Uh, Snail Bob? Not for nothing, but are you absolutely sure that it's necessary to teleport you across the level so you can stand on one of those blue-and-wheels? If you really need turn around, you could just, y'know, turn around.
In order to earn the badge, I had to play through a second time. I really think you should introduce some random elements so the solutions change from game to game. Heck, even take it a step further, and have 60 puzzles on hand, of which only 30 are randomly chosen, making for a unique experience every time!
FredericS is right. Most of these cards are hard to tell apart at a glance. The reason the standard 52-deck is printed the way it is (1 symbol on an Ace, 2 symbols on a 2, regal woman on a Q, etc.) is because it makes the ranks of the cards easier to identify in your peripheral vision. Especially bad here, because the only thing that matters here is the rank, not the suit, of the cards; yet the most prominent feature of the cards is the suit.
 "Papa Louie 2: When Burgers Attack!"){kind=icon}
 "PuzzleNuts"){kind=icon}
 "Space Croissant"){kind=icon}
 "Monsterland 3. Junior Returns"){kind=icon}
 "Screw the Nut 3"){kind=icon}
 "Happy Tower"){kind=icon}
 "Seeds"){kind=icon}
 "Flip and Go"){kind=icon}
 "N (Official Web Version)"){kind=icon}
 "Snail Bob 4 Space"){kind=icon}
 "Alien Anarchy"){kind=icon}
 "Mystery IQ Test"){kind=icon}
 "Coffee Break Solitaire"){kind=icon}
 "Super Stocktake"){kind=icon}
 "Cyclop Physics Level Pack"){kind=icon}
XD