mission infiltrate: One Room or lots of little rooms?

The screenshot below shows a new map being made in the level editor. (I'm going to add more objects to the game in the future to make is look less 'bare').

But one thing I'm still thinking about is whether to make one room levels like the one above (as this is turning more into an arcade shooter at the moment) or to have a level made up from lots of little rooms, which could mean very big levels overall while not using up as much resources/processing power on the phones.

However having a mission compromising of lots of little connected rooms would add a lot more time onto the development of the project because I'd have to change  both the level editor and the game.  Currently as said it's very easy to make a level like the one above (if anyone wants to make a level, please contact me below).