He manages to beat every. Last. Robot Master. No charges, no weapons, no damage. That is METAL.
And now he's working on doing the same with the Skull Castle bosses. Special mention has to go to his defeat of the infamous Boobeam Trap in Mega Man 2, using amazing dodging skills to perfectly defeat what's often considered to be the entire franchise'sThat One Boss. And the stage rating pretty much consists of him giving it a "Reason You Suck" Speech. (About its difficulty being not legitimate and just plain unfair)
His battle against Quick Man's Doc Robot in Spark Man's stage was quite awesome too, even knowing that it's the successful run, it's so intense that you still end up cheering for him during it.
He managed to beat a Zelda 1 Minimalist Run. That not enough for you? He actually went beyond that, doing a Minimalist Run while also exploring as much of every dungeon as possible. This includes the final dungeon, which not even most regular walkthroughs bother to fully explore (and with good reason). And bear in mind, at the time he started, he had no idea Ganon could Tele-Frag him for a One-Hit Kill under 3-heart conditions. Let me repeat that: he went through the entire final dungeon multiple times, knowing that he could just get unlucky with Ganon's RNG and have to do it all again. He still finished the run.
No less than 5 hours into his Pokemon Emerald No Evolutions run, he finds a shiny. Not to mention this is his very first Pokemon Let's Play. And when asked in the comments if he'd found a shiny before...
In the run, he can only catch and use 30 specific Pokemon. In Part 38, we find out one of them is Feebas. He still catches it anyway.
The way the Champion battle ends. Espa makes up for his incredibly unlucky performance against Juan by surviving Gyarados' Earthquake with 8 HP and K Os with a +6 Calm Mind Shock Wave.
Taking on Alessa's Dream unarmed towards the end of his Silent Hill 0rigins playthrough. For bonus points, the Wii Punch-Out! theme is playing throughout the fight.
This would later happen again in the Pikmin 1 No Deaths Run, where in Part 11, he took out the Puffstool with no Pikmin in the extras. Doubles as a Crowning Moment of Funny.
In the Spyro the Dragon Let's Play, Roahm once again proves he's a Determinator. After footage of one of the levels decides to erase itself, he's unable to record getting that level's collectibles again as the game autosaves. So what does he do? Replay the entire game from the beginning up to that point! Bear in mind he did this and still managed to get the next video out on-schedule.