Wetrix is a 3D puzzle video game developed by Zed Two, the studio of brothers Ste and John Pickford, for the Nintendo 64 and personal computers in 1998, and the Dreamcast and Game Boy Color in 1999 (as Wetrix+ and Wetrix GB respectively). The player's goal is to hold water bubbles falling on a 3D isometric landscape. To do this, enclosures are created with Uppers, which fall in a similar manner to Tetris blocks, that raise the ground. While water can be evaporated with fireballs, hazards such as Mines, Ice Cubes, and earthquakes also fall and ruin the player's construction. The Pickfords conceived a Tetris-esque puzzle game out of a water demo they worked on for another one of their Zed Two games, the hack and slash Vampire Circus. For design, the biggest focus was on the basic elements' interaction with each other, as well as the puzzle game style's originality; the use of falling blocks was the only similarity between Wetrix and Tetris. Zed Two signed a two-game deal with Ocean Software, a week before its merge with Infogrames. It required the brothers to turn Vampire Circus into Taz Express (2000), while allowing the brothers free rein with Wetrix. The PC version was produced from January to October 1997 by the brothers themselves, while the Nintendo 64 port was developed with three additional programmers from around June to Christmas 1997. The Nintendo 64 version sold over 105,000 units in the West, and just above 12,000 in Japan, while the PC version sold 30,000 copies. Wetrix was generally well-received by critics, who applauded its addictiveness and original concept but were critical of the limited camera mobility and divided on its difficulty, steep learning curve, and two-player mode. It garnered the highest rating for a review of a Western-developed title from the Japanese magazine Famitsu Weekly in years. The critical and commercial success motivated Imagineer, developers of the Game Boy Color port, to commission Zed Two to develop a sequel, the PlayStation 2 launch title Aqua Aqua, which made little alterations to the main gameplay.