Way back in 2007, the Wii was still young and desperately lacking the support of hardcore gamers. Previous attempts, such as Ubisoft's Red Steel, had been a disaster, and everything since had basically amounted to nothing more than watered-down rail shooters, such as Resident Evil: Umbrella Chronicles or Link's Crossbow Training. The Wii needed something new, different—something that took advantage of the motion controls in a creative way. The Wii needed Suda51's No More Heroes.
Grasshopper's absurdly violent character action game centers around Travis Touchdown—an awkward, down on his luck Otaku who entered a dangerous assassin's organization just so that he could impress a girl. He accomplishes this with a deadly beam katana, a lightsaber knockoff that he purchased on the Internet. It's cool, it's efficient, and it helps Travis fulfill his nerd fantasies along his quest. But there's a problem.
See, Travis' beam katana isn't perfect. It's flashy and all, but it has a tendency to sputter out after prolonged usage. So to recharge the battery, Travis has to waggle the grip in a rather, ahem, familiar motion. And by "Travis," I mean you have to waggle your Wii Remote (or Playstation Move controller if you're playing the 2010 PS3 port) right along with him.
While making players mimic masturbation with a Wii Remote is fantastic enough on its own, it feels especially at home in the context of No More Heroes. As mentioned earlier, Travis is a rather stereotypical "horny otaku loser" type, and as Suda51 himself puts it, "that type of movement is very Travis." Beyond just being a cheeky gag, recharging manages to take advantage of motion controls to actually put themselves in the protagonist's shoes and mimic a motion that goes hand in hand with their personality.
While motion controls get a lot of grief by gamers, I do think that they're very interesting as storytelling tools. Motion controls can put you into the shoes of a protagonist in a way no normal controller can, theoretically synching your movements up to the protagonist's. While it can certainly be rough at times, simple movements usually work perfectly. Simple movements such as waggling a controller up and down over your crotch.
It's worth reiterating just what purpose Travis Touchdown serves (at least in the first No More Heroes): a mocking player avatar. He plays video games, watches way too much anime for his own good, and fumbles over every social interaction thrown his way. But that's all in cut scenes; while under the player's control, Travis is a stylish fighter mowing down non-stop hordes of armed mooks. His aforementioned awkwardness never comes through during gameplay—until your battery runs low and you need to recharge. It's brief, it's absurd, but it's a great way of pausing the spectacle to remind you how absurd it is that this guy is a feared assassin. While it may seem like a small touch, it's one that really helps draw you into Travis' shoes.
So basically, making a player pretend to masturbate with a Wii remote is actually really cool from a storytelling perspective.