First, what is the difference between the three types of artifacts? I've returned to the game after a couple years (having recently played the Anniversary Editions of the earlier games) and am not seeing it mentioned in game anywhere. They all seem to add towards the same total for achievements.
Second, what is the nature of these stages? Are they procedurally generated? Just seems like a heck of a lot of stages to be in one of the side modes.
Tormented space seems to be based on the DMD with harsher settings than the Prospecter Zone.
As to the AoOs: The types are different, and there is a significant tactical use for them. Essentially, thy are single use superweapons. Once collected, they are usable from the "Orbital" tab, with buttons appearing next to those for the Command Node(s).
Freeze (Yellow): Freeze in place all Creeper, Digitalis and Runners in an area. Also (I hear) stops the countdown of any Spore Towers in the area of effect. Lasts for some tens of seconds.
Mass (Red): Destroys all Creeper/AC/Player units in an area, changes the terrain to level 1 near the impact site, and to level 9-10 in a ring around it.
Convert (Blue): Converts all Creeper in an area into AC. Works especially well en masse or on deep Creeper. Timing a PZ Bertha to land shortly after the conversion can make the AC go further.
Thanks. Wow, totally missed their presence in the Orbital tab. Sure that could've come in handy a time or two so far...