You know it's actually funny your all mention smaller maps cause I never play 2v2 so at the begining of the post I was all "Why make a 2v2 map or a 1v1 map." And then I was like maybe you never play 2v2 cause you hate Crucible so much. To me this is really funny cause the first map I made that was walkable was thepit by scotishalien (The maxscript map editor I made was actually created entirely for him)

this was before I could make the lua files so this is just using the location of objects for prison. If someone would like to work on this map I can send them the source files via a private message.
For those interested btw beach is only about 10 meters longer then prison and I think the citadel is just slightly closer.
I just want to adress to open area question cause this is a sort of a map making nerd thing but the reason there isn't very much open space in demigod is cause of the node system. The AI and Minion use these node things to move around which I think is both to lower memory use and to make pathing easier around complicated shapes. So after you make a map for the player to walk around on you have to make a network of nodes for the map.
Other Node-----------Other Node
/ \
/ \
First Node ------> Second Node ------------------Third Node
\
player's can't walk here
\
Other Node
If you don't make the nodes and summon a minion the game just crashes or your minion freeze in place. And if you place a node over a path that players can't walk (As per my diagram) the minion just walk right over the pit as if nothing is there. Incidentally grunts which come out of portal use their own set of nodes called chains to determine where they walk and will happily fly over pits to reach their goals as well.
Prison actually has a really complicated node system that make the illusion that the minions aren't following predefined paths. Because the max scripting I did has really horrible land node support (You literally can't see them once you click away.) I've tried to avoid open spaces.