Tweaks

Almost nailed the level generation within the Planet/atmosphere classes.
Amended physics some more and scrapped the horrible exponential
equations. There's a slight issue with the calculation for air density
returning a double.NaN which I need to solve, top priority.

Once that issue is dealt with, I can get started on enemies.

Have also looked for outside help with regards to original music for the
game, progress on that front seems to be going good, I've had a few
samples that seem fitting. Maybe it won't be silent by next week when
the enemies are done.