I have drawn an example of what I want to do just to give you an idea of what I'm talking about:

In the sample image there are blocks, a red coin thing that theplayer needs to "pick up" and water.
What I'm struggling with is, how would I "lay out" a platform level? Would I need to individually load draw and place each and every single block manually?
I have used the Tile map samples on the wiki and have thought about using a Tile-based approach to this, but I just don't know if that is the right approach to be using and I'm also unsure of tile map style because in my levels, I will also have "moving parts" (some regular blocks that you think are ground, will suddenly fall into the water when you step on them) So how can I turn a single tile-based block into a movable thing? Also, I need to take into account Camera. I'll need to move along with the player as he gets closer to the right-edge of the level so that more of the level is revealed.
Any help is much appreciated, and sorry for the long post!
Does anyone know of any working platform sample games that I can learn from, or where should I start from to make a proper platform game?