PS Vita Homebrew Tank War has been updated bringing us to version 0.42.  Tank War was created using the PS Mobile Suite SDK.  Tank War 0.42 was released by PS Vita devs lightmeng and Kyin12.  The Tank War developers have added in some nice new features such as a battle mode and a map editor.  Listed below you will find the instructions on how to play Tank War.  You can also view a full developer statement at the source.

Directions

single:
up and down, left and right (direction) + △ (shooting) with the left stick
Double:
Player 1: up and down left and right (direction) + L (shooting) with the left stick
players 2: the △ X “○ (direction) + R (shooting) with the right stick
button by touch
has been added joystick and touch control old : temporarily did not join the rocker == ( Time is too … did not have time to look at the joystick manipulation is the Editor optical want say ) when you need to forward to achieve basic functions … after

Source