GNUjump is a clone of xjump aka. FALLING TOWER, it uses SDL and has a lot of more options, it also supports multiplayer.

GNUjump 1.0.8 with wincrash theme, watch in SDLjump theme

It has much more options, you can change game settings, such as FPS and trailing effect; video, such as using OpenGL and antialiasing; and sound volumes. Beside the must-have high scores, a replay feature, so you can watch other peoples playing.

The sound effect is hilarious, not your usual sounds, but someones vocals, watch the video and you will hear those.

Here are the four themes.

SDLjump theme (default)

xjump theme

Windows Crash theme (wincrash)

Auri theme

GNUjump was created by Juan Pedro Bolívar Puente in 2004 as SDLjump until the end of 2006, written in C with SDL under the GPLv3, currently version 1.0.8 (2012-07-25).