Before I get "leedle ur an n00bz0rz" in the replies I'll just make myself clear now: I know all backgrounds use Layer 2, I'm just horrible at making titles. Moving on...
Layer 2 is either a static background or a blank background (unless you use HDMA you scrub) to make way for interaction. I'm sure I'll get a few yesses and nos here, but has anyone utilized setting tiles to act like tile 25 with interactive Layer 2?
For example, you have some clouds in the background, rigbt? So you have the ground in Layer 1, you got some dirt, bushes, grass, all that good stuff, and then suddenly you run into a situation where you want to maybe put coins in front of something? It'd be a waste of processing (unless you have an SA-1 ROM) and ExGFX space if you had tiles mixing the coins with the green bush color in the background, and probably a little time-consuming too. So what do you do? You switch the level's mode to one that lets you interact with layer 2, and put coins in front of a bush in the back! You can even add more detailed and varied backgrounds with this. The catch? Well, you'll have to stick with 16 screens only.
Oh the agony of not having overly long levels to troll with. If you disagree with my sarcastic statement, watch this video
, skip to 30:13, and tell me how long it takes to get to where the screenshot ends in the TAS. Now that you know it takes approximately 32 game seconds to get there in a TAS, imagine a fully-filled castle level or a Kaizo puzzle level instead of a grassland that's the exact same length. You're looking at about a whole minute of gameplay, but that's only with a TAS, possibly using glitches. If a human player is playing it blind they can take a LOT longer considering they're not going to make one-frame wall jumps or glitch through walls or do a credits warp or make pong and snake with arbitrary code.
The only two drawbacks I can think of is of course the 16-screen limit, (of 0F screens if you're a nerd) which isn't even bad as I explained, and the fact that generators that affect Layer 2 scrolling are also affected. So if you want spikes falling up and down and a bush with coins in front of it at the same time, you better learn how to use that ExAnimation. Other than that I've actually used this method a couple of times, and my backgrounds look pretty good, especially with an HDMA background to make it a bit more vibrant.
So what do you guys think? Are you convinced that you can make some better backgrounds or will you stick with regular backgrounds?