NS-Tower is a shareware computer game that was originally produced in the late 1990s by Nagi-P Software for the Macintosh, but later ported to Windows. The game is unusual in that it only requires one control: either the space bar or the mouse button.
NS-Tower is a platform game in which the player attempts to climb a tower. The main character continuously moves back and forth across the tower at a constant speed. When he hits a wall, he reverses direction, even if this happens in the middle of a jump. Holding down a button causes a meter to fill up. When the button is released, the main character jumps to a certain height based on how full the meter was at the moment of release. If the meter fills up, it goes back to empty and begins filling up again. A player loses when his character falls off the bottom of the screen. It is not possible to "win," though NS-Tower does keep track of the top five scores at each skill level.
NS-Tower was announced in January, 1996. The latest version, NS-Tower 2.5 (English) was released for Windows on July 9, 1997, and no updates have been released since. A Java version appeared on the Nagi-P website, but it is presented as an alpha version, and has not been updated since December 31, 2000. This version lacks many features of the Macintosh and Windows versions, including top scores, springs, moving platforms, conveyor belts, levels of difficulty, and platform layouts that become more difficult as you climb. This makes achieving a high score in the Java version a simple matter of time, rather than the combination of luck and skill required in the standard version.
The most recent releases (in 2003) have been for various Japanese cell phones, including NTT DoCoMo.
The Japanese version of NS-Tower for Windows appears to have been updated more recently than the English version, but the download link is broken. It is unknown whether Nagi-P will continue development of NS-Tower and its sister game, NS-Shaft.