Possible features

• terrain based levels on planets (asteroids would have to be replaced with something else)

Planned features

• upgrades (grabbed ingame, can be purchased permanently in shop)
• primary weapon upgrades
• bombs
• shield upgrades
• hull upgrades 
• powerups 

• destroying asteroids to find upgrades and asteroid ore (currency)
• fighting multiple enemies: alien and human space ships, battle stations etc.
• levels with rising difficulty and different backgrounds (planets, galaxies etc.) 
• space derbis
• highscore tables (preferably online)
• different game modes
• fast paced gameplay
• landscape mode view
• different types of steering (tilt and touch, xperia play support)

(list of features not final, subject to change)