"X-Scape, known in Japan as X-Returns (X-RETURNS（エックス リターンズ）) and in PAL regions as 3D Space Tank, is a first-person combat simulation game developed by Q-Games and Nintendo released on the Nintendo DSi's DSiWare download service. It is a sequel to the Japan-exclusive Game Boy title, X.
Players control a commander who has returned to his home after a decade-long tour of duty. However, an evil warlord has taken control of the entire planet, forcing the commander to take control of an enhanced version of the mobile spacecraft from the game's predecessor, VIXIV. Throughout the game, the player will visit 20 different planets as well as completing a number of main missions and side missions.
X-Scape is seen in a first-person perspective. It uses the Nintendo DSi's top screen to show players' surroundings, while the bottom screen acts as a means to control the game and a radar. Moving the stylus to the top of the bottom screen causes players to move forward, while moving from side-to-side allows players to look around. Pushing any of the d-pad or face buttons causes the players' tank to fire. There are two types of missions: tunnel and planet. In tunnel missions, players control the tank, attempting to escape through a narrow tunnel as fast as possible, avoiding barricades, attacking foes, and collecting coins to add to the constantly ticking down timer. In the planet missions, players are able to freely explore the area. They must destroy a set number of enemies throughout the world in order to progress to the next mission. Players are able to fly into the air by hitting pyramid-shaped ramps. Several secrets can be found throughout the game, including an ability to fly into the air at any time. Other tasks on the planet missions include searching for bombs in order to deactivate them, as well as hackable buildings that reveal the game's backstory."
Source: Wikipedia, "X-Scape", available under the CC-BY-SA License.