Add summary notes to level design docs

docs/level_design.md

@@ -44,7 +44,7 @@ The following guidelines are here to reduce friction between the player and the
 ## Making Space
 As our game is heavily focused on mobility, and makes use of a third-person character, we need ***lots*** of space for navigating, attacking, and moving the camera.
 
-Here are some guidelines for creating engaging spaces:
+Here are some guidelines for creating engaging spaces. Remember that 1 meter = 100 Unreal Units.
 - Minimum of 7.25 meters width and 8 meters height in hallways
     - Preferably, incentivize players to stay in the middle of the hallway
 - Minimum of 15 meters width and 10 meters height in rooms
@@ -148,3 +148,10 @@ If you think something enhances an experience but challenges these guidelines, *
 Have other devs try it! Have playtesters try it! If it enhances the game, then you've successfully iterated.
 
 See other project guidelines [here](../README.md#resources-and-guidelines).
+
+# IN SUMMARY
+- **Keep things spatious.** If it feels overly-spatious in editor, you're probably on the right track
+- **Mix things up.** Give the player a few things to think about at any given time, unless directly teaching them something.
+- **Use the tools.** As before, variety is the spice of life!
+- **Scale up the difficulty.** Use arenas for set-piece encounters, and use increasingly difficult enemy spawns and arrangements as the player progresses.
+- **Keep it going.** We're only going to have one or two levels after 18 months of work. Make those levels count in both duration and impact!