Played this again today. So far the only criticism I can think of are the first and last points. It seems like both the first and last points tend to stalemate into a "blockade" kind of stand off, requiring massive brute force to breach.
On the first point, I honestly can't pin it... Might be the bottleneck right before the turn after the uphill fight, but I'm not sure.
The last point it seems to be because it's too "wide" with very little cover, making for some great sentry camping. So long as they have some support, sentries seem able to cover almost the entirety of the final room by themselves, thus constructing a few in key positions ends up covering the whole room with crossfire. Suggestion would be to maybe add some route straight behind them, or add some cover on the back area, so a single sentry can't cover the whole thing. On top of that you have to move the cart all the way to the middle of their base. It's like the end of badwater (which so often stalemates), but a bit longer and with no overhead positions to "bomb" or snipe the enemy nests from.
Another, minor, detail is that it's impossible to visually tell when the cart is supposed to "finish", since the glass area is huge in comparison to the "point". That, however, can be easily solved by either adding a "hazard-strip" overlay around the exact point where you win, or, as some suggested in the server, moving the winning area to the start of the glass.