I spent a small amount, so I can't say I play totally free. I will wait to see if the proposed improvements in balance and bug fixing works before I commit too much.

However I spent a small enough amount that it is nearly the same as free. I see several ways to play and advance free or close.

Facebook friends gifts can help a lot. Conquering a level 10 NPC can solve many many level 10 issues and quests you may have. Being organized can help a lot to make sure you dont spend too much time online. (log on, do your attacks and get off) Plan ahead for food problems if you have too many troops. Keep barracks running 24/7 draft extra troops from your colonies....the list goes on.