(click for larger resolution)
A common complaint I hear from my factorio-playing friends is that the game is simply too easy - you just sit in your base, fending off the occasional biter attack, and once you have built some advanced weaponry you move out and bulldoze all enemies in your way. I have attempted to rectify this problem by making a map in which you are forced to constantly battle challenging, if not overwhelming, enemies. A map in which, with the exception of some starting stone and iron, every resource field is guarded by the enemy. Most importantly though, a map in which you are on the offensive from the very first minutes. The result, which I called The Oasis, pleases me enough to release it to the broader Factorio community. It's a save file, not a scenario, so put it into your Factorio\saves folder.
https://www.dropbox.com/s/o9cmtrz8o50e1zx/oasis.zip
The result of an 16 hour play-through are seen in the tab below. I've used no mods in it.
Spoilers