Man i love this concept, I'm honestly surprised it's not been done till now (to my knowledge) since it goes hand in hand with the "Infiltration" feeling you get from a good Capture the Flag map!
The map feels pretty simple in most areas - which is a smart choice when testing something new like this out, but I can already tell by looking at what you've got that it'll work, so I say you start getting more complex with the execution.
The flag building itself has a nice flow, but can get pretty "winding" once the flag's at the top.
You want this last flag to be more difficult, but making a player run in a spiral (like the god forbidden 2fort stairs) doesn't necessarily improve the gameplay itself. (quick positive note - the cage at the top is great, as preventing rocketjumpers really presses the increased difficulty.)
So here'd be the hard choice: The current 'stacked' layout you have does a great job explaining to the players how it works -it's very clear where the flag will go next. Now how do you keep this subtle communication while also changing the flag placement's to improve how it's played?
Here's some basic ideas to get the ball rolling:
The podium!.. (like 1st, 2nd, 3rd, it would break up
the symmetry and allow some refreshing changes within.)
The Bar Graph!...
boasting a clear progression - for this one I would suggest
changing the enterances as well
The ladder!.. (similar to the bar graph, but giving a pathway to the new level through the original intel area,
this could deter engineer's sentries from becoming irrelevant after each capture... possibily.
It should be stated these concepts would 1. include a heavy rework of the building itself (I believe for the better, asymmetry builds better gameplay AND aesthetics) and
2. only be considered once you've satisfyingly play-tested. I don't have the faintest idea how the intricacies of the map pan out.
Here's the bigger kicker
The mid is quite uninspired. I felt the TFc influence there, but not in a good way.
I see no reason to get rid of the lower tunnels, but at the moment you only have 2 "elevations," with the pure middle just being a flat pit.
In Anchor-Action areas (like a mid), you usually want a minimum 3 layers of elevation, but more than that, you want something central to move around.
Tf2 is loved for it's movement, so make use of it! Something to run under, something to walk over, cover, jumper, go crazy!
I've found it's always better to
overdo the height variation and have to tone it down, rather than build it up. Maybe you can make a nice third layer that merges with the main route, as you only have the two flanks to
the flag at the moment.
Technicals aside, I already have hopes for this premise. fighting and sneaking your way into a higher and higher goal is quite a motivating idea, and I trust you to hit this theming
HARD. I love me a desert night map.
This will be the perfect projects to broaden your horizons and understanding of flank. I wish the best of luck for you!