To be fair, the original Zero Ring was quite cramped. I'll suggest that maybe you should add a little more geometry and detail below for the player to go through and look at, because at this point this is turning into a remake rather than a port. At least give some ways for Tails and Knuckles to pop in and out of nowhere, or some protection for them to get out of Sonic's crazy speed. In a level like this, Sonic will be flinging around like in Meadow Match. I truly believe that if you take some time to put more detail into this level, you would have yourself a fun arena. Try looking back at the original level for inspiration on how to remix the original and add a little more to the theme!
I have a few suggestions on what you could do:
- The floating platforms, springs, and the moving platforms. They played a large role in the level. Maybe form some platforming to reach up to items such as a weapon or a random monitor? Add some structures or rooms or towers to transcend? But don't make it too exclusive or too high or you'll cause the lower floor to feel stale. You need to encourage the possibility of reaching up to heights to gather more than you could in one area alone. The same applies to every match stage, big and small, where the player goes a little out of the way to get some of the more powerful power-ups for the level. In this case, you might want to look at auto, rail, and possibly bounce.
- The ditch in the middle of the stage. Maybe instead of making it one deep hole down, you could formulate a difference in floor height, and place computers or some pretty effects to give the feeling of a technological experience.
- The Brak art. Maybe you could go a little further than having a painting pasted onto a ledge, and make a Brak 'statue', and have a little commemorative establishment that can also be wandered around, and at the top of this wonderfully evil shrine, you could have a competitive weapon panel, like Meadow Match does?
It's just a few of the ideas that came to mind. But when you take some time to think about it, and put your mind to the creative side of you and be patient, you can come with some pretty clear answers. don't be afraid to look up the Wiki for what you need to do to make your map a show, it's your world and your passion, seek answers if you really need them.