Talk:Excavation/@comment-24.74.4.230-20141013220120/@comment-24.74.4.230-20141016030841

not sure if its random or set when you get keys, i havent paid that close of attention, but i did get a third key at 1100. so its probably worth pushing to there if you can handle it. much passed 1100 or 1200 and it starts become pretty difficult to keep the machine alive. the enemies just start doing too much damage and they can really hurt it in the time you need to run for batteries.