Hi, I'm new to this forum and not 100% sure if this is the right place to post something like this. Me and a partner are designing a 2D platformer game for mobile. We have been in the designing phase for awhile. I have an early level design that I made with tiled. Just was wanting feedback on how it looked and what may need a changed or added for better quality.

Thanks.

[attachment=26809:FirstPictureNinjaScroll.png]

1. What moves, and what doesn't move?
2. What's harmful, what's inert, and what's helpful?
3. How clearly are all of the above communicated while both objects and the level are in motion (scrolling)?

Almost everything is a mid-tone of gray. Like Ashaman73 says, the contrast is on the low side. Using a greater range of value to separate objects more clearly, and then adding even just a single hue at different saturations, e.g. for atmospheric perspective, can do a lot.

Examining your image close up, I noticed that you had shadows for the platforms. That's excellent! But because the shadows are pretty much the same color, as well as projected straight down, they're not terribly visible or helpful gameplay cues.

I took the liberty of making some minor, very quick adjustments to your image to illustrate what I'm talking about:

I added some blue tints to your ninja; red to objects that are harmful—the bullets, the spikes; and different grades of orange-yellowish tints to the platforms and background, to give them a measure of atmospheric perspective. I also added drop shadows to the platforms and the bullets, so that they get called out to the eye.

Again, I've done this without knowing any details of your game design, but my recommendation is to think along these lines and see if subtle additions can't do a ton for your graphics. Cheers!