Mm... it's not MapMaker that's bad (heck, I think a lot of the default maps made through MM are better than most any maps, regardless of being made via MapMaker or PolyWorks). You just need more practice with it; the first few maps are always the most annoying.
Try to avoid dead ends in gameplay. If you study the original Bridge, you'd see that the terrain allows players to move around in very seamlessly motional directions. Your add-ons lead to dead ends, which force players to eventually return back the exact same way they originally came from. Loop the landscape so it stays circular and interesting to players.
The colors are a rather poor pick; your color choices are predominantly white, green, and red; if a lot of polygons are the exact same color, they get visually boring very quickly. The trexture is another visual problem; you don't want a texture to repeat itself over and over again, especially how it is clearly shown in the left side. Stretch it out and make it look interesting, and perhaps even achieve a 3D effect.
To sum it up: I've seen far worse remakes, heh, but try to keep visuals in mind, and most of all, focus on having a good layout; remember, people are playing on the map, so be very careful with the structure of the landscape, which is almost always what makes or breaks a map.
