The middle green button is the minion inventory where you can change place with a minion. It exchanges afterwards with a "turn back to Necromancer button".
if you revive enemies after combat they stand up again and disappear after 2 seconds. You will find a new entry in your minion inventory then.
About the controls stopping to work and the view I will have a look. I will probably push an update after jam then. But thank you for the feedback.