You want to end the world and this portal is the key. feed the life force of your victims to the portal to summon imps to do your bidding and protect the portal from anyone trying to stop you.

'WASD' to move, 'E' to interact with the portal, 'Mouse' to guide imps, and 'Left Click' on enemies to target them

The important fix version fixes a major issue where the price to end the world was 10 instead of 100 and where right clicking froze the imp's AI.