add an animation that shows the spacecraft flying away into the far universe when flying out of the screen

record statistics like the following, per game and in total:

• total distance traveled
• total angle turned
• full rotations made
• total obstacles avoided
• fuel consumed
• number of near misses
• number of power-ups consumed
• distance traveled in the wrong direction
• number of collisions
• number of deaths by collision and by other causes

get some extra score or score multiplier for:

• near misses
• high speed
• good coordination (turning on thrusters simultaneously)

just for decorations purposes

• planets
• stars
• spacecrafts
• humans/animals/aliens
• funny things

add a final screen which shows the score, some statistics, a highscore list and gives the option to restart (maybe when all buttons are pressed for some time)

Add an explosion animation on collision with obstacles

Add power-ups that can be collected and give you a special skill for some time. For example:

• don't die at collision but bounce
• double scoring
• better control (more friction?)
• repair kits/extra lives (only makes sense when you don't die instantly on collision)
• a magnet to attract other collectables
• freeze obstacles so they don't move
• become smaller
• delete obstacles

negative collectables could be possible, too:

• attract obstacles
• earn only half of the score
• worse control (less friction, more power)
• damage
• make obstacles faster
• become bigger
• more obstacles