"This is a first-person shooter that was released in May 2004 for the Tapwave Zodiac, which re-uses many sprites (e.g. enemies and HUD weapons) that were already used in Duke Nukem 3D and consists of 21 short levels set in locations such as streets, strip clubs, cemeteries, mansions and a futuristic dirigible. In order to pass from a level to the next it is necessary to kill the enemies that are present in the current level, until one of them drops a key card that will enable the access to the next level." Source: Wikipedia, "Duke Nukem Mobile", available under the CC-BY-SA License.