on last, the low ground entrance is a little like cardinal last. and in my experience that area of cardinal is dead space that no one really bothers with because it's too big of a disadvantage to be down there. maybe consider making it more like snakewater's low entrance, where you can still push in through it at least occasionally.
on second, that battlements/sniper spot on the top left of defense can watch far right, the low entrance from mid, and the left path to the point. seems too strong, especially because it's hard to bomb (you can skip across top of point pretty easily but the sniper can also duck into the tunnel). a small adjustment to an existing fence would block the lower sightline.
i like lobby a lot. i think it would look better if the left and right ramps up from lower weren't symmetrical.
i got the overall impression there were slightly too many ways to get everywhere. especially around mid.
you can stand on the barbed wire fence on two. dunno if you intended that or not.
the demo rollouts have a lot of potential.
high ground on two seems too strong. a soldier can sit up there, spam every entrance. scout can deny bombs. also, there are several places you can stand as demo where you can see your traps on all four paths from mid to two, including some opportunities for deep traps. i feel like most maps punish demos for watching deep traps by forcing them to overextend a bit, but this one doesn't.
one of the entrances into last should have a shutter.
*take this with a grain of salt; i just jumped around for a while, haven't played on the map.