There are so many things wrong with this.
1) The flat used. I'm assuming you figured out how to do custom textures and flats, and I must congratulate you on that much. Unfortunately, you proceeded to use it towards a completely illogical end. Why on Earth is Sonic's face plastered on the ground a thousand times over? It makes no sense in any context, and is a waste of time. I won't say don't make custom textures, but try for things that are actually textures and not just random images you want to splatter over a wall.
2) The rings are flat on the ground - at least, I'm assuming, since I can barely see them, but I'll get to that aspect in a bit. There should be a flag for the ring Things - either "Deaf" or "Float", depending on your config. Make sure they are always checked, unless you're manually placing the rings in the air yourself. Failure to do this is a typical telltale sign of newbie mapping, and needs to be corrected posthaste. It's pretty simple to do, really.
3) The level design leaves a lot to be desired, even considering I can barely glean anything from the screens in question. It's flat as hell, and frankly, every good map for a Doom-based game, SRB2 included, has some modicum of height variation, even if only some minor variation to break up the monotonous vast plains you'd get otherwise. So, yeah, unless you're trying to recreate Wolfenstein 3D in SRB2 (and believe me when I say it's already been done), start adding some platforms, maybe something small to jump on for a ring box or what have you...
4) For the love of Jegus, type "bind z screenshot" (or any key other than z that you prefer, really) into the console and use THAT to take screens. Screens with a console taking up half the screen are hideous as shit.
5) If you do ever intend to continue showcasing this map, or any other, I highly recommend you take multiple shots showcasing different angles of the level, as opposed to the two here which are the exact same shot taken at different times. I've literally got one image to go by here, it's not really easy to work with.
I'm sure there are more flaws, but they're likely covered in the Level Designer's 101 than IE linked to. Do read that over and figure out what you're doing wrong other than the things I mentioned, and maybe you'll start churning out something interesting. As it is, this screams "first map", and I'll be honest, nobody's first map is worth giving a shit about.