Requirements & Running the game

At least an MSX1 machine with 16Kb of RAM. 
Insert cartridge on any slot and switch your MSX on. 

The Story

Dr. Shorizawa has lost his collection of marble balls inside one of his experimental machines. What a mess! 
But he's an evil genius so, somehow, he managed to trap two big boys, reduced them to the size of an average mouse and sent them inside the machine! 

Those guys are Galarto and Toruga, powerful monsters that can destroy entire cities. But now, reduced, they can't do much to escape from Shorizawa's machine except follow his instructions to recover all the balls for him.
Galarto is strong and usually can throw radioactive breath out of his mouth (now, not so much) and his punch is very powerful. Toruga is a bit more polite. He can give some good help.

Controls

Use Cursor keys or Joystick to control the kaijus and Space or Joystick button 1 to punch. To switch between Galarto and Toruga, you can CTRL, GRAPH, CODE, or SHIFT keys, or Joystick button 2.

F1: To pause/unpause the game.
F2: To change between 50hz and 60hz   mode. 
F3: To change color palette between MSX2 mode or a more classic MSX1 palette. Only for MSX2 or higher machines.
ESC: To commit suicide. In case you get trapped somewhere!

How to Play

You are trapped inside a set of levels filled with enemies, traps, ways to open and that kind of nasty stuff. Collect keys to open doors, activate switches to open paths, avoid or neutralize enemies. There are plenty of balls to recover, so get them all in order to activate the EXIT and go to the next level. BOTH kaiju have to exit the level to complete it! 

Important: Cooperate! You control both Toruga and Galarto but never at the same time. Switch between them to get the most of their distintive skills. As they are usually located at different points of the level, some can access to some parts that his mate can't. You can only switch at safe floors. That means you can't switch while being over a mine or a switchable floor, for example. If at some place you can't switch, just move.

Use punch to activate stuff. Like... open doors (if you got the key of the same color), switches, move some blocks... Punching also can stun enemies for a limited time! As said, Galarto is stronger, so his punch will paralize them for longer than Toruga's punch. Anyway, be careful, they will move again once the punch effect is gone. You can't kill them!

If you keep Space or Joystick Button 1 pressed and then, without releasing it, you change your direction, your character will look towards you indicated WITHOUT moving. This way, you can face enemies and stun them without getting out of a safe position.
There are some Info Boards around. Read them to get some clues, sometimes... and  passwords! 
Every level has a number of Balls to collect and a time to complete it. You can get extra time by getting hourglasses or by freezing more than one enemy at the time in the same screen, but it will work only once, until you leave the room.

Walls and Floors:

Normal Walls: They  limit the rooms.  
Breakable walls: Galarto can break them, if he can see where they are (check items).  
Doors: Open them with keys of the same color.
Info board: Some provides a tip for the level, some are just a message from Dr. Shorizawa and some will give you a password!
Green Switch: To switch some floors on and off, allowing the player to walk over them.
Red Switch: At some levels there's a Raft. You can remote-control it with this. The Raft will move in the direction you punch the Switch.
Yellow Switch: It forces the Slider enemies to move. 
Moving Block: They block some paths. You can move them by using your punch.
Ghost Wall: You can't walk over them, unless you are invisible (check items).
Fence: They dissapear if there are two frozen enemies on the room!
Mate's Face: Also, the place where your other mate currently is, will be represented by an icon that shows his face.

Normal floors: They're totally safe to step.
Switchable Floor: It becomes a wall or a floor after using some switch. It can be the Green Floor Switch or the Green Switch. 
Stopper Floor: Prevents Moving Blocks to be moved over it.
Arrows: They force the player's movement into the direction they indicate.
Switchable Arrows: They work as normal Arrows but you can change their direction using the Arrow Switch.
Ice: You will slide quickly without control.
Trapdoors: They will open after you pass over them.
Teleports: They will teleport you to another teleport of the same color.
Water: At the bottom it's full of Oxygen Destroyer, so it will kill Galarto! Toruga, being a turtle, can swim better and avoid it. 
Lava: Only Galarto can walk over it without being burnt. 
Acid: Deadly. It is chemical waste enriched with Oxygen Destroyer, so it will kill both kaiju.
Mines: Warning!! If Galarto steps over them they will explode! Toruga is more prudent and can step over them carefully.
Bridges: They appear after you use the Red Floor Switch or the Double Floor Switch. That will allow you to avoid water or lava.
Green Floor Switch: Stepping over it will switch all the Switchable Floors on the level. The ones which were up will go down allowing you to pass over them, but the ones which were down, will go up blocking the pass.
Arrow Switch: It changes direction of the Switchable Arrows on ALL the level.  
Red Floor Switch: It can do two things. One is to activate the bridges to allow walk over water or lava zones. Other is to convert the Acid into Water/Acid. NOTE! When in the game there's a different set of graphics, like red floor and walls, this Switch is Blue Floor Switch.
Double Floor Switch: This does exactly the same as the Red Floor Switch, but needs cooperation! One kaiju will have to step over one switch and his mate over another switch of the same kind located anywere else in order to activate it.
Exit: Once you got all the balls, it will blink and BOTH kaiju can exit the level.
Raft: Sails over water or lava. Jump into it to direct control the raft into any direction or use the Red Switch to control it remotely.

Collectable items: 

Keys: They open doors from the same color.
Boots: Allows you to walk freely over the Arrows and over the Ice.
Glasses: Get them to see breakable walls. Remember that only Galarto is strong enought to break them.
Poliya's Sign: Poliya comes to save you.

Items for inmediate use:

Hourglass: This gives some seconds of extra time when Galarto gets it. If it's Toruga who takes it, it will freeze time for some seconds, making enemies slower.
Heart: Gives you an extra live.
Invisibility: Makes your kaiju invisible (not inmune) and allows you to trespass the Ghost Walls. Also, turrets that shoot can't target you.

Enemies:

Crab: Walks from side to side.
Skrew: It goes up and down. simply.
Paul, the octopus: Like its friend Crab, BUT it can move over water and lava!
Ika: Same movement as the Skrew BUT can also move over water and lava.
Spark: Can move more or less in circles around some area.
Moving mine: Like Spark, but in opposite direction.
Swirl: It wanders around following some walls.
Slime: It has more complex movements.
Slider: It is stopped until you press the Yellow Switch. Then it will move until it finds a wall.
Roller: Like slider but no switch needed, it will detect when you enter a room a then move. But... if you are invisible, it can't see you.
Turret: Doesn't move but can shoot! But if you are invisible it can't target you.