The information in this video is taken from a leaked interview with an unknown developer.

00:00 INTRO
01:01 Phoenix
04:02 Phalanx
05:44 Cow/Animals
07:05 Memory Limitations
11:27 Worm
16:04 Griffin
19:50 Monkey
26:15 Roc
29:19 World Map (Various Colossus + Locations)
32:34 OUTRO