I'm not sure about the creature upgrade system; I have mixed feelings. On one hand, it's cool to have additional buildings and to be able to improve weak units into something decent. But on the other hand, these upgrades look a bit awkward on some units: imps, unicorns, etc. Also, most of the upgraded units don't have their names changed; instead, words like "master," "lord," or "arch" are added. It feels a bit repetitive to constantly upgrade units from dwellings. Why can't they just be upgraded directly? And after the upgrade, the un-upgraded versions become useless. I'm not sure if these upgrades should be removed altogether or if they should be limited to only certain units, like in Heroes of Might and Magic II.