The fact that I'm taking my time to write all of this up means that I actually see potential in this, so take it as praise in its self. Here's my suggestions:
- It looks pretty good, what with its original art style and identifiable location-specific geometry, but the top section looks to be nothing more than a pistol-jerk on a pair of split hills. You'll definitely need some suitable cover-scenery or structures to fill out that area and make some interesting inter- and intra-area sight lines.
- Your plank ladder needs a bit more cover - I'd recommend breaking it up into two shorter ladders with a small spire with a mini-plateau (kinda like TF2's Badlands spire, but without the spiraling paths and top mesa) bridging the two, not only to make it less of a strict ascent, but also to add mid-way cover.
- Your rope bridge could use some handrail-ropes on the side as well, since those using it would most likely be strafing, rather than looking ahead. Having one small section of the handrails cut could not only add a localized hazard, but also more character.
- Be sure that vehicles have a secondary way from one side to the other, rather than just the one confined tunnel path. If I'm interpreting the scaling of it correctly, you should probably bring two of the cliff edges over the central basin a bit closer together to allow Warthogs and Ghosts to make that epic jump.
I'm loving everything that I'm seeing so far, but it still needs a great deal of work. Keep at it!