They Are Billions

The difficulty challenges in this game do NOT stack. You must complete easy (150 days), accessible (120 days), challenging (100 days), and brutal (80 days) separately.

Note that difficulty for these achievements are entirely based around the game duration setting. If you are struggling you can play with the minimum infected population (easiest).

It’s probably best to try to knock out some other achievements while you do these , so try to keep the score factor above 100%:

Suggested pathway for all 4 difficuly achievements:

- game 1 :: dark moorlands (120 days + brutal population) = 130% score, the extra 20 days actually makes the game far easier than having less time with a lower population for newbies. Good time to do a “no towers” run.

- game 2 :: peaceful lowlands (100 days + medium population) = 120% score, this map is really easy to expand fast. Good time to to a ranger only run.

- game 3 :: frozen highlands (80 days + 80 days + low population) = 180%, this map will give you the best chance of surviving the shorter gap between waves, by making the most of the increased natural defences and choke points to protect your city. With only 80 days to play with I wouldn’t limit yourself by trying to get any other achievements on this run.

- game 4 :: frozen highlands (150 days + nightmare population) = 110%, this is a great time to go for the no walls or towers achievement as well. The long time between waves and the natural choke points will make it easier to survive using just spike traps and your army.