If the game area is only 1024x768 pixels and you only use 20 or 30 platforms, there is absolutely no need for collision management. Every PC can determine the bounding-box collisions for this game in no-time, as far as i can tell.

What you shouldn't do, is only performing pixel-perfect collision. You should start with simple bounding box collision. If two bounding-boxes overlap, you can start with the pixel-perfect collision detection. Pixel-perfect collision detection is more CPU expensive and you don't want to do it for all the sprites every frame. Only those, whoes bounding boxes intersect.

But who say's you need pixel-perfect collision detection I think its sufficient to have simple bounding-box detection. Keep in mind that bounding-boxes do not have to have the same size as the sprite image. Sprite images are often say 64x64 pixels in size. But alot of these pixels are left transparent and only a smaller rectangle contains the visible pixels (e.g 54 x 32). You should define the boundingbox as a box around these visible pixels. You chould even leave some visible pixels outside the boundingbox (you have to fine-tune this). If you use animated sprites, you should only leave the most static bodyparts inside the boundingbox (torso, feet etc). But again... You have to fine-tune this for every sprite....

Hope this helps.