Do not use just one static sprite batcher for your entire level if the level spans multiple screens of content. Unity will draw the entire static sprite batcher, regardless if only 1% of it is visible. Split them up into logical sections - rooms, pages, etc. Keep an eye on the Stats view in Unity to make sure you aren't drawing a lot more than you expect.
Use the collider set-up to mask impassable ground and platforms. Here is the previous scene with colliders set-up as an example.