Virtual Boy Wario Land

Virtual Boy Wario Land (known as Virtual Boy Wario Land: Secret Treasure of the Awazon in Japan; originally titled Wario Cruise), is the second installment in the Wario Land series. As its title suggests, it was released for the Virtual Boy in 1995. The game features Wario on a quest down the Awazon River that turns into an adventure after an expected relaxing trip.

Story
Virtual Boy Wario Land's story begins with Wario landing his Bulldog airplane in the middle of the Awazon River's basin for some nice relaxation time. However, his vacation from reality is soon put to the end when he spots three Mask-Guys heading behind one of the Awazon's waterfalls with great treasure in stow. Wario, his interest piqued by the thought of claiming the pitiful creatures' treasure as his own, soon follows the trio into their secret cavern behind the waterfall. Although he meets up with the three just fine, he soon finds that they, despite being weak foes, have a secret: a trap door to the deep underground chasms below the Awazon. Thanks to this trickery, Wario soon finds himself in the underground labyrinth deep below the river and swears to seek out his revenge and steal the Mask-Guys' treasure.

Trivia

 * In Kirby Super Star the mode The Great Cave Offensive is somewhat based on this game.