SimTower: The Vertical Empire (originally published in Japan as The Tower[a]) is a construction and management simulation video game developed by OPeNBooK and released in 1994 for Microsoft Windows and Macintosh System 7.

The in-game speed was also criticized for being too slow, which was a crucial issue in the game because time must pass for the player to earn income to purchase new facilities.

They must plan where to place facilities in the tower that include restaurants, condominiums, offices, hotel rooms, retail stores and elevators.

To prevent tenants from vacating their properties, the player must keep their stress low by fulfilling their demands for medical centers, parking lots, recycling facilities, clean hotel rooms staffed with housekeepers, and an efficient transportation system, which involves managing elevator traffic.

If the ransom is not paid, then security services must find the bomb before it detonates, or else the tower will incur significant damages.

The sound effects are kept to a minimum; noises that are played in the background include office "buzz" and elevator bells.

[5] While attending Waseda University, Saito played SimCity on the Macintosh, which prompted him to pursue video game creation after graduating.

He left the company to personally produce the second game, which built on ideas he conceived while working on his first: elevators and towers.

They also appreciated the "homely" feeling of SimTower, in contrast with other Sim games such as SimEarth and SimLife, which they felt were too universal to take on a personal identity.

[8] A reviewer for Next Generation panned the game, saying it lacks the bustling interactivity of previous games in the Sim franchise: "There are bug infestations and the occasional fire with which to deal, but most of the time, SimTower sees you standing around waiting for cash reserves to grow in order to add more floors.

"[9] Australia's The Age found SimTower a pleasing return to form for Maxis, after the release of the disappointing SimFarm.

However, she also felt that SimTower had good replay value due to the non-linear gameplay, giving the game four stars out of five.

They also predicted that players would be unhappy with the game's speed, as time plays an important role in earning money from tenants.

[11] Writing for the San Diego Union-Tribune, Matt Miller felt that, when compared to SimCity 2000 (1993), gameplay in SimTower moved slowly.

[16] Vivarium launched a version of SimTower for the Game Boy Advance, called The Tower SP, published by Nintendo in Japan on April 28, 2005, and by Sega in the United States on March 15, 2006.