NORCO

This is missable, but it's pretty hard to. Right near the beginning of the game, you'll be in your bedroom. Click on Monkey and play both of his staring contest minigames. If you fail, you can try again. Once you've beaten both minigames, the achievement will pop.

First achievement:
Start of game in the title menu. Settings, gameplay, automate combat.

Soon as you are in the bedroom after all the cut scenes, click on the monkey which is on the left of the desk. The Achievement will unlock without having to do anything besides clicking ready twice and picking up the monkey at the end. The game will do it for you with the automate combat ticked on.