Not balanced at all. Normal mode is near impossible, with every higher level enemy oneshotting you.
For anyone asking: The additional ships are unlocked in the higher difficulty modes. Level and XP seem to be completely useless.
@simonsays365 Completed but no badge? If only there was a way to Report missing achievement. Like maybe at http://www.kongregate.com/feedbacks/new?game_id=26389&type=MissingAccomplishmentFeedback
In terms of real time, on my machine, a day takes at different speeds: 1x = 388s, 2x = 180s, 3x = 108s. So, yeh, 3x is genuinely 3x quicker, but still so damn slow.