Clash at Demonhead

Clash at Demonhead (called Dengeki Big Bang! in Japan) is an open-ended action adventure game for the Nintendo Entertainment System.

You take on the role of a soldier named Billy "Big Bang" Blitz, who is contacted during a vacation with his girlfriend Mary about a kidnapping attempt on Professor Plum, a scientist who constructed a Doomsday Bomb that will destroy the world. At the start of his mission, Bang encounters Tom Guycot, the kidnapper. Guycot tells him that he and the seven governors of Demonhead Mountain have taken the medallions used to power the device, and issues a challenge to Bang to try and find them. With no choice but to cut his vacation short, Bang goes off to find the professor and prevent the world from being destroyed...

Not to be confused with the band from Scott Pilgrim. But it's obviously named after the game, which Bryan Lee O'Malley claims was the first NES game he ever had.

Tropes used in Clash at Demonhead include:

• Betting Minigame
• Bodyguard Babes: Mush, boss of Route 16, has a pair.
• Deflector Shield: The Barrier item creates a force field around Bang that blocks enemy bullets.
• Destructible Projectiles
• Doomsday Device
• Everything's Even Worse with Sharks: The appropriately-named Shark, who lords over Route 22. The battle takes place underwater, so you'll need an Aqua Lung to survive.
• Fairy Companion: Faysha.
• Giant Space Flea From Nowhere: The Demon itself has nothing to do with Guycott or the Doomsday Device. Interestingly, it shows up at the middle of the game, and nobody, good or bad, saw that coming.
• Guide Dang It: There's no way to know where to find Shark..to find him, you have to push against the bottom of an otherwise unremarkable all-water route to find the boss room.
• Hopeless Boss Fight: The Demon (the first time you see him). You're required to lose to him the first time you meet in order to advance the story, and can't harm him without using the Sword of Apollo.
• Jet Pack
• Lava Is Boiling Kool-Aid: A Supersuit is mandatory to even go anywhere near it.
• Luck-Based Mission: Disarming the bomb. You have six tries to correctly place all of the medallions, and the Magic Countdown speeds up every time you fail to get them right. Compounding matters, the combinations are randomly generated with each game, and you're never given any clues as to what medallion is supposed to go where.
• Meaningful Name: Guycot is a pun for the Japanese word for "skull".
• Monster Is a Mommy: After you defeat the Demon, you stumble upon a room full of his/her/its eggs, which you have to destroy before you can escape its lair.
• Name's the Same: "Professor Plum" has nothing to do with the board game Clue.
• Nintendo Hard
• Non Lethal Bottomless Pits: Subverted. While falling into pits doesn't kill you, you get taken to an area where you have to fight your way back to the surface, making you start the route over again.
• Oxygen Meter: The timer for the Aqualung acts as one. Once it runs out, you lose one point of health for every second you're underwater.
• Painfully-Slow Projectile
• Password Slot Machine: The bomb disarmament sequence.
• Plot Coupon: The medallions.
• Power Floats: Acquiring the "Levitation" power-up allows Bang to float around in the air for a short time.
• Sizeshifter: Max, the Governor of Route 7, starts out as a tiny runt of a boss, but as you damage him, he increases in size until he's big enough to float around and start firing smaller versions of himself at you.
• Skippable Boss: Pandar.
• Spread Shot: The Big Shot/Thundershot weapon fires a powerful spread of projectiles, but has limited ammunition.
• Sprint Shoes: The Power Boots boost your running speed for a short time.
• Sword of Plot Advancement: The Sword of Apollo.
• The Unfought: Tom Guycot. He attacks you at the very beginning of the game, but after you get tricked into releasing the Demon, the Demon curbstomps him offscreen and steals his medallion afterward.
• Villains Never Lie: Subverted. Guycot lied about the number of medallions...there are really only six. Pandar, one of the Governors, doesn't carry one. Guycot had his medallion stolen from him by the Demon.
• Warmup Boss: Gazh, the boss of Route 11, is usually the first one players fight, and he has a very predictable fight pattern (dash back and forth, get shot, shoot a line of fireballs, rinse, repeat).
• Weaponized Headgear: Mush like to toss his mushroom-shaped cap at you.
• We Sell Everything
• Xanatos Gambit: The Demon possesses your "ally" Michael and uses him to trick you into releasing him.