Luigi's a big green ball of contradictions. He likes to act the tough guy and in the Paper Mario series he's often heard bemoaning the fact that his big bro gets the lion's share of the adventures, but let's face it, he's just not cut out to be the hero.
He's as cowardly as green custard and his mental skittishness is embodied in his every moment. Compared to Mario's composed, precise moments, Luigi floats around the Mushroom Kingdom as though his feet were made of tiny, startled horses.
Leaps see him flutter high and far into the air as if determined to crash into something before he hits ground. While Mario at full pelt can screech to a halt on a sixpence, Luigi's momentum keeps him going for just that little bit too long, like a caravan slowly tipping over a cliff.
The Gangly Green One's wild movements make him a far harder beast to tame than his brother, which in turn makes this DLC pack a far tougher proposition than its parent game, even before you consider any of the other changes.
Despite the colour of the box, this is not a game for greenhorns. New Super Luigi U positions itself as the Lost Levels to New Super Mario Bros. U's Super Mario Bros; a punishing gauntlet of ultra-tough levels geared to expert players.
Stages are dense with enemies and light on breathing room, with later levels spaced with lonely, isolated platforms and moving podiums that swoop across the landscape as erratically as our unlikely hero. More often than not, they're framed on all sides by crushy spiky pillars or those especially large variants of Piranha Plants.
To reach the pole at the end, then, more often than not you have to sprint through the level at full speed, using your instincts (and a fair few of your extra lives) to find the level's sweet spots. In case you didn't get the memo, you're only given 100 seconds to complete each level - meaning the panic-inducing hurry-up klaxon sounds the instant the stage appears on screen.
New Super Luigi U's haste-driven structure makes sense as an expansion pack. Two-dimensional Mario platformers are at their best when they demand that you become one with the level design, exploiting every last carefully placed koopa and goomba to sprint to the finish line. This is why the time challenges were for many the best part of New Super Mario Bros. U, and it's smart to build an entire game around this ethos. While Luigi U is pleasingly merciless, though, we can't help but feel that swapping Mario for his skiddy sibling isn't a low blow too far.
You might remember that Nintendo released a video a few months back detailing the difference in movement between Mario and Luigi. It seemed faintly ridiculous at the time, but that video is rarely far from your mind during play. You're always acutely aware of the fact you're in control of the lesser of the two bros. Luigi U asks you to tackle expert-level stages with a slightly different tool and it makes nailing the perfect run slightly less intuitive than you'd like.
Upon completing the main game levels do sprout a Mario block that enable you to go back to the original physics, but stages are designed for Luigi and end up feeling a bit 'wrong'. We'd have preferred a level pack that taxed skills we already had to one that threw you into the deep end on your first day on the job.