Astro Chase 3D is a space shooter which transfers most gameplay mechanics of its predecessor Astro Chase into a first-person perspective. In the future, aliens try to destroy Earth by sending Mega Mines toward the planet. Now the player needs to use the Ultraship and destroy those mines before they reach Earth!
Each of the 40 levels takes place on a confined field in which the player needs to find and take out the mines - the level is lost if a mine reaches Earth or when the ship is destroyed by enemy fire. The most important tool is the radar which shows all important things the player needs to be aware of: Earth, mines, enemies and the position of space stations which give positive effects when approached: energy generators replenish the ship's energy, shield depots give temporary shields and power-up stations deploy extra weapons. There are overall four weapons available: a standard shot, a more powerful shot, energy seeking missiles and decoy mines which attract enemies.
While the game offers different control systems for various input devices (mouse, keyboard or gamepad/joystick), the basic idea is that the ship moves forward on its own and the player only controls the direction. This allows to shoot independently from movement, although the player needs to enter a different mode in order to control the weapons. The ship's movement can also be halted completely. There are overall 40 levels, including five practice levels. Beating a level unlocks the possibility to start directly from five levels before (i.e. beating level 20 allows to start from level 15) after exiting the game.