Thanks for playing and sharing feedback! I like the target practice idea! I initially had some plans for downtime activities but had to cut scope because life got in the way. Unfortunately that means the game ended up feeling slow with big gaps between waves and nothing really to do in between.
The guards are intended to be used to kill an ogre that gets past you if you notice it in time. The map is helpful in keeping track of that, as it shows an overhead view of the area and any ogres, but it seems like some players haven't figured out the map either. Did you unlock it and did it work/make sense to you?