Maze of Galious

"Story: Popolon went into Mt.Atos to rescue Aphrodite kidnapped by Hundos. But it was a trap made by Galious. He attacked the castle during Popolon's absence and also kidnapped and imprisoned a baby from the heaven who was supposed to be born to Popolon and Aphrodite several years later..."

The Maze of Galious is the most influential game you've never heard of.

Released in 1987 for the MSX, Galious has you control two knights, Popolon and Aphrodite, on their quest to rescue the baby Pampas. To do this, you must platform your way through a sidescrolling castle and fight the Great Demons hidden in the depths of ten worlds. Popolon and Aphrodite play slightly differently (for example, Popolon destroys boulders faster), but for the most part they act as two separate life bars. To fight each Great Demon, you have to get the Great Key to its world, fight through the world, discover its name, go to the Demon's lair, and type the name into the keyboard to summon it for battle... and kill it, of course. Doing so rewards you with the Great Key to the next world. Repeat until finished. Simple as that!

Galious is most notable for being one of the first Metroidvania games (it was developed concurrently with Metroid itself, and the two were released in the same year). The entire castle is explorable, with treasures and weapons hidden throughout its corridors, as well as "shrines" where you can commune with the gods to save your game, buy weapons and items, and get advice on the game's various puzzles.

The game is also relentlessly brutal. Character death is permanent, and while each character can be revived once (and only once), it is much more common to restart from the last time you saved if Popolon or Aphrodite die. Furthermore, items are not described in-game, and their function is not always obvious; for example, the Dagger allows you to kill all bats in a room by typing "UMBRELLA," and that's one of the more sane ones. And then there's the Great Demons themselves, who generally deal somewhere between half and all of your life with each attack (and that's with the Cape that reduces their damage). In short: your typical late-eighties video game.

Maze of Galious has gained somewhat of a revival since the release and popularization of the freeware (and now Wii Ware) game La-Mulana, as the latter is explicitly inspired by (and even contains significant shout outs to) the former.

Modern remake is here.

Note: Due to the nature of the game, the names of the bosses (besides Galious) are spoilers and should be treated as such.

This game provides examples of:

 * As You Know: Many of the gods' advice consists of things that Popolon and Aphrodite, as characters, should already know, such as Aphrodite being able to breathe in water.
 * Ballistic Bone: Launched by the first boss.
 * Battle Couple: Popolon and Aphrodite.
 * Blob Monster: The fourth boss.
 * Boring but Practical: Out of all the items, upgrades, and weapons you will acquire throughout the game, the one you will come to love the most is the ring that teleports you back to the save point.
 * Dem Bones: One common enemy.
 * Demonic Spider: Anything you can't hurt from the front. Skeletons aren't so bad once you get used to them (and especially once you get arrows), but knights are just evil.
 * Flip Screen Scrolling
 * Giant Enemy Crab: The sixth boss.
 * Guide Dang It: The title screen happily tells you how to start a new game. It does not tell you how to load an old game. (Press L.)
 * Good luck finding out how to cross the water pit in World 2 without a walkthrough.
 * Noob Bridge: A gate blocks a corridor in the first dungeon, and it's not obvious how to open gates. (The way to do it is to stand next to the gate and hold down the direction control towards it for a certain amount of time.)
 * Old Save Bonus: The game could be made easier by having Knightmare or Q*bert in the MSX's second cartridge slot.
 * Password Save: 45 characters long! Luckily, if you have a disk (or are playing the remake) you can press F5 through F9 to save your password to disk instead.
 * Schizo-Tech: At the end of the game, you are equipped with: a sword, arrows, two varieties of magic fire, and... land mines.
 * Sound of No Damage: A hollow "ping", accompanied by the projectile ricocheting off.
 * Stock Femur Bone: First boss throws these.
 * Super Drowning Skills: To be fair, they're wearing armor. (Although Aphrodite is perfectly fine with breathing under water for some reason.)
 * Wake Up Call Boss: Conditionally. Most bosses have a weapon that is meant to be effective against them (not a weakness per se, more a tactical advantage). If you don't have that weapon, they will promptly inform you of such in no uncertain terms.
 * Where It All Began: That door in the room where you start the game? That's where Galious lives.