Here is the list of differences with the final version :
* There are ONLY 2 Solar Systems (three in "Gravitar
* Different Planet, Bunker and Fuel Cell icons.
* Different bunkers' and planets' shapes.
* No planet animations.
* Stronger and more intense Gravity (Game-play is much harder).
* Some sounds are different during the game.
* There is an additional 'Low on Fuel' warning if the fuel level drops below 2000 fuel units that is not present in "Gravitar
* Rammer ships are present in the south planet of the second solar system - Not in "Gravitar