[quote:35d80yd5]as well as splitting the two large terrain pieces into many small pieces.
I don't know if it's the images that are causing your hiccup. But if it is your images, then it's not just a matter of chopping up large images into small images.
You have to make modular tiles. Create a handful of selected pieces that can snap together to make larger, complex shapes. For instance, you have a lot of large areas that are filled with basically the same empty, black space. You don't need all that blank space, it's just taking up VRAM. You can use a simple 32x32 black Tiled Background and stretch it. Or if you plan on texturing that area, you can use a few simple types of tiles that that layer over each other and repeat them.
And just so I'm clear... no you can't just take the large platform sprite and erase the middle part, because blank space in a sprite takes up just as much memory as colored space.
As for the outer surface of your platforms... it appears that you want to have something that doesn't look like it's repeating. That's fine, too. Just make a small set of raggedy looking tiles (maybe twenty tiles or so) that you can fit together in different configurations so it doesn't look like it's the same tile over and over again. You might get a few similar looking areas, but you can disguise them with decorative stuff.
It's just not a good idea to draw a large area of terrain, ever. It's wasteful. Yes, making tiles and fitting them together like puzzle pieces is more work... but it works. Games use tiles and repeating textures for a reason. One kind of tile with 20 instances is much more efficient than a single sprite of equal area.