Radical Highway graphics

[pyroslasher]

In my searching for materials to use in my next level, a level based off of Radical Highway(I am making it mainly because I now have Sonic Adventure 1 and 2 to draw inspiration from WITHOUT watching videos of it and just basing the levels off of that). Radical Highway is a Shadow level in the game Sonic Adventure 2 and its remake Sonic Adventure 2 Battle that was put into Sonic Generations as a Modern and Classic Sonic level and with its music used in the Shadow the Hedgehog two-player mode. It also made an appearance in one of the Mario and Sonic at the Olympic Games games apparently.
I got a city tileset to use, and I was happy with it since it looked like it would work, but I realize something. Sonic Adventure 2 did alot of things like railgrinding, an apparently obsession with box breaking and picking up random and useless objects, ect. But, seeing as it is a Sonic game, that's the thing I'm thinking of the most. It has robots to fight against. Not goombas. Not koopa troopas. Hell, not even Bullet Bills(though they would fit in Radical Highway, but that's off topic).
I searched for robot sprites and found nothing besides SMB3 styled Mecha Cheep Cheeps. The city tileset I have is SMW styled, and there are no fish in Radical Highway in general.

http://sonic.wikia.com/wiki/Category:G.U.N._robots

I would like a GUN Hunter to replace Hammer Brothers and Gun Beetles to replace Flying Koopas. Energy bullets should replace the hammer brother's hammers.

Here is the song that will be played in the level, just in case you need to know: