Super addictive. To be fair, I still don't really get what the best strategy is, especially at the beginning, so I'm getting steamrolled by human opponents pretty easily...
Get allies at the beginning so that you may aggressively conquer bots without worrying about being conquered. Those ally may cross you, but they'll have a penalty so they are disincentive to do so.
There's a lot of luck involved too, sometimes you'll just get dogpiled by two neighbours and there's not much you can do, but at least it's fast.
In the beginning I tried out a bunch of ratios and never found any strategy that seemed to have worked. Now I just leave it on default for entire runs, won a handful of times in free-for-all, seems to work out OK for most cases.
In the first ~1 minute or so I keep 1K soldiers "at home" at all times, and whenever it goes above, I send them out in the "non-taken land", so basically medium-sized expansions until there is no land left. Then start attacking bots in the order of the money they have available, and once there is no bots left, start attacking humans.