How should Tails' gameplay be like?
I always saw him as someone who spins a lot. Sonic has his "Spindash" where he turns into a ball, Tails should have a "Spinswipe" where he turns into a saw or something and spins like a beyblade, like how he does in SA1 when you get the purple thingy.
Then, that could be used in lots of ways. Like, if there is a giant screw below him, he can screw or unscrew it by spinning. And whereas Sonic's spindash is about getting horizontal speed on land, Tails' spinswipe would be about getting vertical speed in the air, so his levels should be highly vertical and about him getting to higher and higher places. Spinning being his thing would also contrast his Nemesis Speedy since he also spins to attack.