GYATM Alpha 3

Alpha 3!

We're deep into finishing up the ending, bughunting, and tuning now.

Bugs fixed:

1. Units can no longer overlap
2. Units have an actual price
3. Endgame unit can now be built
4. Build dialog has an obvious cancel
5. Mystery helicopter bits cleaned up
6. Days/Turns dependency created
7. Turns now 10 seconds, days now 6 turns

New stuff:

1. New unit to allow the endgame to start
2. Colony ship built!
3. Pilotable Helicopter