Tetrisphere

In most Tetris titles, a player's score is incremented by completing "lines", where a row of brick pieces without gaps is removed from the 2D playing field. This action both earns points and clears the completed row, creating space for additional pieces. However, in Tetrisphere, the objective is to remove bricks by causing three pieces of the same type to touch as a result of a "drop". A drop occurs when any brick falls, either directly from the player releasing the currently held brick or when the supporting brick below it is removed by any means.

When three bricks of the same type touch, this triggers a "combo". During a combo, the three bricks glow brightly and implode, removing themselves from the playing field. Any other same-shaped blocks that are in contact with this combo will also be removed in a chain reaction. For example, if a player has lines of nested "Z" pieces and then drops another "Z" directly on top of one of the nested "Z"s, the dropped piece will cause the piece below to implode, subsequently triggering the removal of all identical pieces touching that piece, and so forth.

Tetrisphere was developed by H2O Entertainment, a game development company founded by Steve Shatford, Christopher Bailey, and Michael Tam, which was based in Calgary, Alberta, Canada. The project originally began as an Atari Jaguar game titled Phear and was showcased for play at Atari Corporation's booth during the 1995 Winter CES, featuring gameplay akin to the "Tower" challenges found in the "Hide and Seek" mode of Tetrisphere. However, it required players to create a hole of a specific size (e.g., 3×2) at the center of the sphere's core to advance to the next level. Nintendo reportedly acquired the rights to Phear after witnessing the game at WCES '95, and it was subsequently announced as a Nintendo 64 title at Nintendo Space World later that year. H2O, which had completed a reverse takeover with Canadian Entech Resources Inc., began working exclusively for Nintendo during the game's development.

Around the time the company went public, Nintendo announced that Tetrisphere would be released in October 1996, which initially boosted the company's stock. However, this announcement did not benefit the partners at H2O. "That was the first they had heard of the release date", stated Canadian Business magazine. The company endeavored to complete the game by October, but this proved to be unfeasible.

Tetrisphere received "generally favorable" reviews according to the review aggregation website GameRankings, based on nine reviews. Critics widely praised its innovative design, numerous and engaging modes of play, and its funky soundtrack, which allows players to select their preferred tracks. Jer Horwitz wrote in GameSpot that Tetrisphere "is precisely the sort of game that the Nintendo 64 really needs, offering revolutionary gameplay, impressive long-term value, and a set of visual effects that go above and beyond what Sony's PlayStation can handle".

The graphics were also generally well-received. Horwitz, who experienced the game's demo as Phear at the Consumer Electronics Show, was particularly impressed with the significant improvements made over the original Jaguar version, noting the smooth spheres and dynamic 3D backgrounds.