ゴジラくん 怪獣大行進

Godzilla is a Game Boy video game developed by Compile. Although it was released in 1990 (1991 in Europe), all of the monsters are from the Showa generation. The game is a port of an edition from the MSX console. Also the international version is slightly different from the Japanese version (different in-game character designs and behavior of the enemy characters).

Various monsters that Godzilla had previously defeated, have kidnapped his son, Minilla, and hidden him somewhere inside the Labyrinth of Matrix. It is up to Godzilla to fight the monsters' attacks and solve their many puzzles, all while navigating a much larger maze.

Monsters-
Godzilla: The first playable character. He must punch boulders through 64 levels, in order to find his son.
Minilla: Godzilla's son, who was captured and placed in the heart of the Labyrinth of Matrix. He is only seen in the end, and does not appear in any of the levels.
Baragon: A slow moving enemy.
Mechagodzilla: One of Godzilla's main rivals, with a speed that is slightly slower than Godzilla's.
Hedorah: A normally invincible monster, that can only be defeated by a boulder, a spike pit, or a lightning bolt. He is also the slowest in movement.
Anguirus: A mutant ankylosaurus that is usually an ally of Godzilla. Normally is a regular paced enemy, but once he is leveled with Godzilla, he will charge at a high speed, making him the fastest in the game.
Rodan: A mutant pterosaur that, just like Anguirus, is usually Godzilla's ally, but now an enemy who flies after him, making it harder to avoid damage.
Ghidorah: A mutant space dragon. After about two minutes, Ghidorah will appear. Having both invincibility and flight, it is very hard to make it past him. He can't be killed by anything. Ghidorah also flies in short bursts.