This Week's Waste of Time
Probably my favorite of the bunch, this minimalist take on Where's Waldo? has players looking into a virtual microscope at a few or a bunch of identical germs. You control one of them, and it's up to you to figure out which one. The difficulty ramps up quickly and I wished there had been a level-reset function in a few places, but Microscopia is an interesting puzzle that the author will hopefully flesh out and polish. That last party sounded dirty, sorry.
T in Y World
You're the letter "T" trying to find her way to the letter "Y." You'll encounter consonants, vowels, and a few numbers and symbols along the way that help and hinder your progress. The game's creation tool isn't terribly user friendly, but the very inclusion of such a tool in something made in 48 hours is worth checking out.
Sirus the Virus
It's a platformer that's freaking difficult. A loose ripoff from Give up, Robot.
Probably one of the most polished entries, even if it is only a point and click game. The way I interpret the game, you are a hipster intern at a laboratory researching evolution and mutation. Or something like that. Trial and error is all there is to it, but the process is enjoyable nonetheless.
I've seen this kind of needle-point pixilation art style a few too many times lately, but it still makes for a charming ambiance. That plus a story about robot drug addiction, you really can't go wrong. Should take about 10 minutes to complete.
A Super Mario Summary
Pretty much what it sounds like: Each level of SMB is shrunk down to one screen. Collect all the coins and reach the top of the flag pole for extra points. It's a cute idea and surprisingly difficult toward the end, but it really makes you appreciate the perfect jumping mechanic of the original.