- Estimated achievement difficulty: 2/10 [Achievement Difficulty Rating]
- Offline: 43 
- Approximate amount of time to 1000: 10-15 Hours [Estimated Time to 100%]
- Minimum number of playthroughs needed: 1
- Missable achievements: Seen It All (30G)
- Does difficulty affect achievements: No
- Unobtainable/glitched achievements: No
Step 1: Complete the Game
Your main task at first should be to simply follow the story. There are a number of side-quests you can pick up along the way, but only a handful are required for the achievements (they unlock journal entries). I have listed those in Good Company (30G) below. You can free roam and complete any quests after the final boss if you'd like, and will need to grind some experience to get to Level 50, so anything you don't do here can be mopped up at that time. It's worth doing the chess games as soon as they are available to avoid backtracking though.
As you play through the game, check Elysium from time to time and upgrade what you can, as well as upgrading your weapon in the armory. If you play the game on Easy, you'll never need to worry about any other equipment as the game is a joke (except for the final boss). I followed this walkthrough which has solutions to all the chess games, puzzles, and side-quests.
MISSABLE: There is only one achievement that you can miss in the game, which is Seen It All (30G). For this, you must ensure you unlock it prior to defeating the final boss for the To End It All (15G) achievement. This is because some of the journal entries must be unlocked with the parrot in your entourage (he tells you a story), and after the final boss that character is no longer travelling with you. Be sure to sleep at camp fires until it unlocks before doing the final quest.
Step 2: Finish Journal and Level 50
You should finish the story at around Level 45 if you were diligent in killing everything in your path. There is a nice XP farming spot listed in the Power From Discipline (30G) achievement to knock out that achievement. If you were careful and did all side-quests during the story and fully upgraded Elysium and your weapon already, that should be your last achievement. If not, finish up any remaining quests or upgrades necessary now to finish off the completion.