Amagon

A 1989 Platform Game for the Nintendo Entertainment System, developed by Aicom.

Amagon is a run-of-the-mill Marine who has the unfortunate luck of landing on a deserted island, armed with only his trusty machine gun and 300 bullets. Said deserted island is overloaded with spiders, scorpions... and anthropomorphic beasts? Who are, sure enough, all out to get Amagon. The good news is, Amagon spies a boat on the crescent-shaped island, which could lead to his escape. The bad news, of course, is that it's on the complete opposite end of the island from where he lands. Though one more bit of good news for him - there's an item to be found on the item called the Mega-Key, and by getting it, he can turn into a musclebound-behemoth whose punches pack a wallop well beyond what his gun can do.

This game has examples of:
 * A Wizard Did It: The game implies that the island's strangeness is due to the influence of.
 * Book Ends: Since the island is crescent-shaped, you can see the opposite shoreline at the beginning of the first stage and the end of the last.
 * Cast From Hit Points: The most powerful attack in the game is a laser that Megagon can shoot from his body, at the cost of two hit points.
 * Death Throws: Turning towards the screen and throwing his hands up, Mario-style.
 * Half Human Hybrid: Each level has a Mini Boss that's a mashup of a person and a large, powerful animal.
 * One Hit Point Wonder: Amagon. One of the reasons that Megagon form is so useful.
 * Pistol Whipping: Amagon's attack when he runs out of bullets.
 * Power Up Motif: Megagon gets his own theme, which will override the current music.
 * Scoring Points: Valuable for once, because each 5000 points you have when activating the Mega-Key results in an additional hit point for Megagon, up to a maximum of 70,000 points to convert into 14 hit points.
 * Transformation Trinket: The Mega-Key.
 * When Trees Attack: Devil Tree, boss of Zone 2.