During his LP of Super Mario Sunshine, he was running out of time in a red coin mission, with 10 seconds and 2 coins left to find. He jumped into one room and that had a coin, he jumped out and ground pounded on a certain floor and dived for the last red coin...and got it with 2 seconds left.
Two episodes later they do the World 8 temple in one attempt.
In Part 16 they pull off most of "Prehistoric Path" in one attempt. Not so much the difficulty as the way they manage to power through despite being hit with all the 'visual stimulation' of the level's mechanics for the first time.
Josh and Super Jeenius managing to beat the Pirate Treasure chase level in Rayman Origins despite it constantly glitching out and killing them right at the end for no reason.
Winning the Gaming King of the Web by three times as many votes as all the other contestants combined.
In episode 22, he fails to plan out a logical order for running around a planet with disappearing floors to collect all the notes and ends up doing it in probably the most ill-advised way possible...and still gets it on his first try.
The very last star in the LP is Loopdeswoop Galaxy, which Josh worries about because he tried to beat it many times when he last played the game and never managed it. Not only does he do it on his first attempt, he beats the best time!
The team behind the Kickstarter collectathon platformer "A Hat In Time" asked Josh to playtest the game for them, and even made an alpha build specifically for him with his name in the version code.