You may find half of the achievements noted with "(Req:Long, HC/Difficult, Raiders)", which means: Long mode (50 regions to defeat), Hardcore or Difficult mode, and Raiders available.
I don't recommend playing Hardore mode - any critical hit or stun may ruin your efforts.
Raiders make game with difficult mode even harder, as you cannot leave your village without proper defense or without paying attention to it. Attackers may kill your villagers, which costs you gold (+risk of starvation and death).

#1 Boosting your equipment. You may have noticed treasure chests lying at random places, containing mainly parts of eq. The trick now is to speed up getting end-game eq. You'll have to avoid all high-level opponents and their attacks/projectiles.
Head to the outermost regions, searching for chests along the way. You may need a mid-tier eq to survive while doing this. Take advantage of the pause (spacebar) and map (tab) to avoid any opponent, also keep in mind that you can check chests during the pause.
This could take more than one attempt (new games), as each death decreases your fame (which can lead to game-over), also your run may result in no usefull equipment (or no hi-tier chest at all).
As you find your stats pleasing, like 10 def armor and 14 att weapon, you may turn back. Next tips could also help achieving this one.

#2 Getting rid of starvation. Hero starts having one common skill upgrade and one ability. With some luck, you may have Resourceful ability which gives 1 food production, thus solving starvation problem. Unless you've chosen to play orc, you are not going to starve anymore even with no villagers settled. You may postpone setting your village up till e.g. having enough cash.

#3 Whole-map hp regen. It's all about gaining Resilient ability or choosing character already having it, like Dwarf Warrior. Moreover, you should always focus on boosting your defence. This should result in fewer home-returning, saving you some time.

#4 Utilizing obstacles. You may find various obstacles, which block movement. Get yourself a bow. Once you get into troubles with 2 or 3 enemies, make them run after you into obstacles, in such way they cant reach you. Try to shoot them to death or separate them (easier to kill solo). Rememer that AI will try to get around the obstacles, so pay attention to your possition while shooting.