Monster Rancher Explorer is a puzzle-platform game released in 2000 for the Game Boy Color. It deviates from the traditional Monster Rancher gameplay by placing less attention on collecting and breeding monsters, and more focus on completing levels.
Monster Rancher Explorer features the same gameplay as Solomon's Key (a puzzle-platform series also by Tecmo) with a Monster Rancher theme. Cox must climb a tower and get through the levels by creating crates to reach his destination while avoiding the monsters, who will kill Cox upon contact.
Monsters cannot be raised in this game, though a few of them help Cox out when he obtains a disc piece. To obtain a monster, you must first collect 4 pieces of a Saucer Stone (or Mystery Disk). Then you must get a certain item in a certain stage, which opens up a bonus round. There you fight a Monster, and upon defeat you can touch the monster to add it to your disk. Once it's regenerated, the Monster is ready to help your character.
Players start out on a map resembling a storybook. You then choose which building you want to go to- the Tower, the Save spot, the Level editor, the Shrine or the Daycare. Once you climb a room in the tower, you can start back there even when you lose all of your lives. There are 60 levels in the castle to play, as well as the bonus "basement" stages. Every 10 levels, Cox fights a boss monster where he must defeat the enemy before taking three hits.
The following monsters can become your ally, and help you in the following ways:
- Hare: Increases your moving speed
- Gali: Temporarily stops the timer and freezes enemies
- Tiger: Defeats all monsters in the room
- Suezo: Shows all items and treasures hidden in room
- Golem: Destroys all crates in the room
- Mocchi: Makes you temporarily invincible
The following monsters make appearances as in-level enemies:
- Octopee (called Tacopi)
- Psiroller (called Rhinoroller)
- Blue Flame (could be an early Sakaruka)
- The Japanese version is known as "Solomon-Cox's Adventure Quest of the White Tower".