Band of Brothels: Some towns have brothels in them, where heroes can pay for a night of fun. It gives them a boost of experience points.
Beef Gate: A trio of Steroid Men will attack you if you go too far south. They'll maul a small, lower-level party, but can be easily dispatched later with a stronger squad.
Big Applesauce: New York City plays a big part of the game, particularly towards the second half. The Empire State Building, Radio City Music Hall, the United Nations Building, Carnegie Hall, and Times Square are all worked into the plot.
Big Eater: The Iron Tummy, of course. And Mademoiselle Pepperoni loves her pizza, and has the body to prove it.
Conservation of Ninjutsu: There's a "danger" level in each sector of the game indicating how strong the enemies there are. Because it's a relative constant, the smaller a group of enemies is, the tougher each of them will generally be.
Treader Man is a genetically engineered half man, half boat, due to microchips from a boat ending up in the process. His biography mentions that he cannot see another boat without pondering whether it is, in fact, his father.
Disaster Scavengers: Just about everyone, to an extent, and the Superhero Leagues in particular. Part of their job is to reclaim lost relics from the pre-apocalypse days for educational and archival purposes. Of course, this being a Meretzky game, these relics are items like celebrity diet books and the recipe for Silly Putty. And a souvenir rack is an important (gold-plated!) historical relic. Even though no one knows what a "souvenir" is.
Meanwhile, one mission has you destroying what is probably the last Frank Sinatra recording to complete the mission, but no one really seems to mind that.
Gameplay and Story Segregation: Powers either work in combat or puzzle screens, not both. There are a couple puzzle that you should be able to solve with attack powers(frustratingly, this includes several of Dr. Entropy's plots), but the game doesn't let you. Like you probably kill dozens and dozens of robots with the Induce Rust power over the course of the game, but when one blocks you on a stairway, your only hope is to trick him into drinking a bizarre cocktail of things you've picked up in early missions.
Guns Are Worthless: There are a few conventional firearms in the game, but they're eventually outclassed by other ranged weapons, including something called a bowel disruptor.
Hermit Guru: The Wisest Man in the World, who you need to find in order to learn how to get to Carnegie Hall.
Holding Out for a Hero: A strange variant, as in the course of the game you visit the territory of two other superhero leagues. However, the areas where they're headquartered will continue to be menaced by mutant miscreants unless your team, the embarrassment of the federation, takes care of it for them.
Improbable Weapon User: Everyone in the League, thanks to the wonderfully bizarre weapons you acquire throughout the game. A modified jet engine, a swarm of trained hornets, arsenic-tipped deer antlers... you name it.
Improvised Armour: Your heros will wear pretty much anything for protection, thanks to the game's giant supply of comedic clothing. Who needs traditional armor when you can wear a diamond-studded chastity belt or a mortarboard inexplicably made of concrete?
Ironic Nickname: Captain Excitement, who is so horribly dull and lethargic that he developed a superpower from it.
Kleptomaniac Hero: While the League is sworn to upholding the law, this IS an Adventure Game, so you'll still grab every item in sight, even from private property.
Literal Metaphor: In addition to telling you how to get to Carnegie Hall, the Wisest Man in the World will also let you use his piano.
Lost Forever: Generally averted. You can drop weapons and armor when fleeing from battle (and money), but as long as you keep winning fights in the same sector where you lost the item, you'll get it back eventually. None of the plot items will ever actually be lost, either.
Mix-and-Match Critters: One of Entropy's schemes involves cross breeding sewer rats and racehorses to develop large, ultra-fast rodents that will terrorize the city. Mercifully, you can put an end to it before having to witness any of the finished product.
Non-Combat EXP: The game gives bonus XP for discovering every area on a map (how hard this is varies, since different terrain types have different requirements for being passable) and for completing missions.
Old Superhero: King Midas, who was quite something in his youth but is pretty much washed-up when he joins the League. His inability to properly work his Midas Touch (which turns things into mufflers) is used for both comedy and as a surprising puzzle solution.
Plot Coupon: You can't attempt the Entropy quest in each set of missions without doing the other four jobs first, as completing each one will provide an item you need to tackle Entropy, or to simply get to him in the first place. To the game's credit, these items tend to be pretty creative and clever.
Sequence Breaking: There is exactly one point where you can ignore the requirement and complete the Dr. Entropy mission first. In the third series of missions, you have to get past a bodyguard who likes to collect not-quite-spherical objects, in order to get to the roof of an airport control tower. However, if you spend enough time leveling to get past the Beef Gate of Steroid Men, you can get enough Really Good At Treading Water power to swim to another airport control tower to fly an abandoned helicopter back to the first one, and defeat Dr. Entropy. However, this is pretty pointless, as you'll need to finish the other four quests eventually anyway, and the four not-quite-spherical objects have no other use.
Plunder: The party will sometimes discover a pizza box or other weird storage object after combat, which will contain loot, traps, or both. Mademoiselle Pepperoni can use her powers to see if the pizza is trapped before you open the box, and if it is, a dose of the Vanquished Baked Goods power will eliminate the delicious threat. If you don't have those resources available, though, you can still take your chances, or leave the potential loot behind.
Power-Up Food: Beef enhances a hero's Brawn score, vegetables boost Health, and fish increases Brains, which makes combat superpowers more potent. These items are in limited supply and tend to be expensive, but they're good investments, especially early in the game.
Railroading: Rather literally, as you'll need to use the subway system to reach certain areas, and each line requires its own access card of the same color. Certain cards, naturally, will only become available later in the game, either by finding or purchasing them. While Sequence Breaking is technically impossible, sly players could theoretically sneak into high-end areas and purchase elite weaponry, while Save Scumming to avoid random encounters.
It's possible to avoid the Steriod Men Beef Gate mentioned earlier via deft leveling and careful navigation of New York City and the attached sewers. Eventually, assuming you survive, you can reach various towns that sell the Treading Water isotope, and with enough money and isotope, you can reach most of the maps in the game long before you finish the second set of missions.
However, there are also only so many random encounters in each map screen. After which only battles that take place in a specific location will still occur on that screen. Meaning that money and experience points are finite resources in this game.
Rule of Funny: While the combat in the game is numbers-based and requires some decent strategy, the messages detailing the attacks of friend and foe alike are utterly ridiculous. Yes, that enemy is a Cy Young Cyclops... a beefy cyclops inexplicably wearing a baseball uniform that throws brushback pitches at your head. And when you defeat him (often by charging the mound with your weapon of choice), his manager decides he's all through and sends him to the showers.
Running Gag: Tons, as per Meretzky's style. The longest-running one is on the chatterbox, which runs a series of stories about dogs biting men in the Weehawken area (or vice versa), wondering whether 'the Weehawken area' is a geographic location or a euphemism. It escalates to the point where Cerberus actually appears and starts mowing down every Weehawken in sight. Thankfully, this is only a side joke and not something the League actually has to handle. There are also themed enemies which have stronger brethren as the game goes on. (The lowly Albino Wino eventually gives way to the Albino Rhino, and then the dreaded Albino Dino.)
Squishy Wizard: The brainier members of your squad (who excel at combat superpowers) tend to have lower health and toughness, making them ideal for the back of your squad. This can be remedied to some extent with vegetables and strong armor pieces, but those are in limited supply and are best given to your front-line fighters.
Standard Status Effects: Subverted. Instead of the bog-standard effects your characters can get like being petrified or poisoned, members of the SLH have to worry about becoming paranoid or getting a rash.
Straw Feminist: Mademoiselle Pepperoni. This trait is actually useful when solving a certain puzzle.
Suicide Attack: Many enemies in the game have one, with a name befitting their character. (Lawyers will Sue, for example, while a Bureau-Crat will Spew Red Tape.) It does a fair bit of damage to almost everyone in the party.
Super Not-Drowning Skills: Being able to swim is the primary power of two party members, and something you have to drink scientific isotopes to give other characters.
Super Serum: The heroes can drink isotopes to gain secondary superpowers. These are permanent, though, and don't seem to have any ill effects.
Super Zeroes: Pretty much the game's entire premise, at least on paper. A guy called Robo Mop that can clean up big messes, for example, doesn't seem like much of an asset. Of course, there wouldn't be much of a game if the League was completely useless, so all of your goofy abilities actually prove to be quite useful as the game progresses. Having to deal with a avalanche of hot peppers when your League happens to have a guy called The Iron Tummy seems a little contrived. Or, perhaps, Mission Control only assigns you jobs that your team is ideal for...
The only superpower that is completely and utterly useless for the duration of the game is the "Create Organizational Charts". Which, naturally, is the main ability of the Crimson Tape, who represents the player.
This Looks Like a Job for Aquaman: No matter how strange or silly a superpower is in this game, there will be a quest that requires it, or an enemy that is weak to it. Except, strangely, for Create Organizational Charts, the superpower of League leader The Crimson Tape. Unless you consider his organizational power to be choosing squad rosters, doling out power-ups, equipping his teammates, deciding battle strategy, etc.
Unwinnable: It's possible to permanently run out of the item that lets you walk through mountain terrain squares.
Video Game Stealing: One-Armed Bandit enemies will sometimes steal some of your cash instead of attacking you. Since money is a finite resource in the game, this is often the more painful choice of the two.
Villain Exit Stage Left: Entropy almost always manages to escape after you foil his latest scheme, using methods as absurd as a talcum-powder bomb or a poorly-made horse costume. Even if you do catch him, he just busts out of containment in time for your next batch of missions.
We Buy Anything: The pawn shops you see in most towns, which both buy and sell a strange assortment of random items. They'll purchase all but the most useless junk you can find, other than weapons and armor, which have their own stores.
What Kind of Lame Power Is Heart, Anyway?: The main character (you) is the Crimson Tape, with the ability to create organization charts and data in thin air. This ability is useful exactly zero times, but it does qualify you to be the leader of the League, if only because you're obviously very good at getting things and people organized.