Out of the box is a one man's project made in the Unreal Engine. It's a 'super Meat Boy' styled game with a lot of jumps and swings all put in a cardboard coat.
I mainly focused on getting it bug free (of course) and creating a nice atmosphere, all of it was scripted in Unreal Engine with the help of blueprinting.
I used Mixamo for the basic animations, but edited them myself later on. I think it feels pretty polished for my first solo game project ever,
hope you enjoy as well!