Actually, the problem with the controls goes a little deeper than you seem to think: it's a mismatch of player expectations versus how it works. Even if we included gamepad default controls, most players would still call the game slippery when they first started playing it. The reason is because SRB2 has a button that 3D Sonic games entirely lack: backpedal.
In 2D Sonic games, if you get moving really fast and let go of the controls, you keep moving for quite a while unless you press the opposite direction. In official 3D Sonic games, if you get moving really fast and let go of the controls, you dead stop almost immediately. In SRB2, it works a lot like the 2D games, but since the game is 3D, people expect to just stop when they let go of forward, when in reality if they want to stop they have to hit the brakes. This is made even worse by a bug if you're going extremely fast that makes the directional controls do almost nothing, forcing the player to tap the brake first and THEN try to maneuver, something that as expert players you probably do without even thinking, but to a newer player it makes the game's controls feel unresponsive because to most new players, the backpedal/brake key simply does not exist.
While we as developers still struggle to try to figure out how to explain this to the player, someone introducing the game to a friend doesn't have this issue. Simply tell your friend that in order to stop in the game, you have to hold the brake. Generally the moment the player figures out the braking mechanics is the point when SRB2 goes from a slippery mess to pretty fun.
In 2D Sonic games, if you get moving really fast and let go of the controls, you keep moving for quite a while unless you press the opposite direction. In official 3D Sonic games, if you get moving really fast and let go of the controls, you dead stop almost immediately. In SRB2, it works a lot like the 2D games, but since the game is 3D, people expect to just stop when they let go of forward, when in reality if they want to stop they have to hit the brakes. This is made even worse by a bug if you're going extremely fast that makes the directional controls do almost nothing, forcing the player to tap the brake first and THEN try to maneuver, something that as expert players you probably do without even thinking, but to a newer player it makes the game's controls feel unresponsive because to most new players, the backpedal/brake key simply does not exist.
While we as developers still struggle to try to figure out how to explain this to the player, someone introducing the game to a friend doesn't have this issue. Simply tell your friend that in order to stop in the game, you have to hold the brake. Generally the moment the player figures out the braking mechanics is the point when SRB2 goes from a slippery mess to pretty fun.