Multi-user Online game        edit
SciFi mostly
4X  Explore, Expand, Exploit, Exterminate
Also includes:
Tower Defense
  (digging down in dungeons can unleash hordes of robots/monsters/undead/etc
  tower defense keeps them from overrunning your settlements)
  What will the max range for tower defense nodes be?   Anti-air?  Anti-spacecraft?  Interplanetary?
Dungeon crawling (many new technologies can only be discovered in dungeons/ruins/caves)
  Beware delving too deep before having sufficient tower defense nodes setup to defend
  against outbreaks...
  Develop tech for automated ruin exploration - explorers, max level?  How much of a level can they do per day?
    Depends on Explorer level.  Level 1 can explore 1/10 to 1/4 of a lvl 1 ruin in a day.  Tech starts at 5% / level * level
    On 2nd level of ruin, 10% chance of finding new tech, 15% on 3rd level ruin, etc
    Planets in systems further from your start world have chance of higher level ruins...
    Tech for auto-unleashing of undead hordes - from orbit - Wipe out your enemies from orbit with ZPoc!
      Requires: tech for auto-sensing horde nodes from orbit and auto-sensing ruins from orbit (+2 levels higher than nodes)
Must develop space travel and FTL
  Only in system exploration is possible until FTL
  Better FTL lets you expand more, find more planets with Elder Race ruins (for the best tech)
Lore
  Elder Race
  Who made the undead?  Was it a bio weapon that got really out of hand?  Can they spread?
Zombie Apolcolypse - never let zombies learn to fly space ships...