I actually enjoy the early game for some strange reason and different map seeds always presented a different set of challenges (especially on deathworlds) because of water, cliffs and resource locations.

I mean, sure - once you get oil and flame turrets it is basically game over for biters and that can get boring pretty quick if you always rush straight to it.

Edit: Also trains. I don't know why but I can just play with trains for hours on end in Factorio.