Beginner map I guess. If the author reads this, I'd say pay more attention to level geometry—it's pretty each to jump off the map or get stuck between walls and boxes and so on if you're poking around. The button in the second-to-last area that opens the door took several shots from the shotgun to open, which was confusing—I actually thought the map was broken and there was no exit for a minute. The secrets were too similar in that they both involved jumping on boxes. Also it doesn't make sense that one of the secrets had a super nailgun, but there's only one box of ammo on the map, not hidden, and no other nailgun.

Still this has waaay more potential than some of the really bad beginner maps on this site. I hope Lukasxd keeps mapping and gets better.

Also, even in such a short map, there should be some more weapons. A shotgun wasn't enough for the difficulty of the battles, and with so little ammo I felt like I could barely use the SNG—I used it to take out the ogres on the roof of the second-to-last area and then had to fight death knights with the boomstick.

Full of Boxes on The Quake Grave

So, FOB was a pretty okay map. The issues I had with it, Lane above has already talked about. My biggest however was that I really didn't understand the button that needs multiple shoots to for you move on. This was super confusing!

Also I think the map should be called "Full of Grunts Hiding Behind Boxes." =)

You don't have to fight the knights at the end. You can just jump on one of the boxes and kill them all with the axe. Not a bad map for a beginner but it is rife with problems, as mentioned in all the comments here.

It's not big, and it's not clever, but it's fun. Five minutes of fun.