Sadly there aren't any.
Well online, You can play as Cream on Sonic flash.
You can try going on SEGA.com and click on play sega, make an account, and you'll be able to play any old time sonic game online. There are also at least a few Sonic flash games. You can try a google search for "sonic flash game" or something similar, or try to find one on game sites like newgrounds.com or such.
The only two games that allows you to play Eggman is Sonic Chronicles: The dark brotherhood and Sonic Adventure 2 / Sonic Adventure 2 Battle.
Super Sonic is not playable in this game.
No, but I do believe a Chao does make a cameo in Sonic Rush when you are about to play 2P with a friend.
There are a plethora of websites that offer Flash Sonic to play for free online, for example puffgames, newgrounds, or allsonicgames. These require no subscription.
No, flv player can just play flash video files, not flash games. You could use Adobe Flash Player to play flash games.
bestupid
It's Dark Spine Sonic. You have to play through the game and collect the seven world rings.
You can only play as Super Sonic in the final boss battle against Ix, and you are automatically turned into Super Sonic.
There are many places where one can play flashgames. Among them are Shockwave Games, Flash Games Player, Flash Games Nexus, Flash Arcade, Addicting Games, and many more.
One can play flash poker games online for free by searching on the internet some websites that offer flash poker games. It is also possible to play flash poker games on phone devices or Facebook applications.