Region-free. Will work on UK/EUR/US consoles.
Sally is slower than Sonic and can't use spin attacks; however, she has a number of stealth and agility-based abilities to compensate and access areas Sonic had difficulty reaching, as well as the use of handheld device NICOLE:
NICOLE Laser Attack: Press A and Sally uses NICOLE to fire a small projectile which hits nearby enemies and obstacles.
NICOLE Downward Laser: Press Down + A while airborne to fire at objects straight below. Sally also gets a small vertical boost.
Slide: Press Down while running to slide on the ground for a short distance. Sally can also slide under certain obstacles using this method.
Somersault Dash: Press Down + B/C while sliding on the ground and Sally will somersault forward at a high speed. This is useful for jumping long distances.
Upward Dash: Hold Down + B/C while on the ground and Sally will rev her feet on the spot as opposed to a spin dash. Let go of Down to charge full throttle in the facing direction. Be careful though, Sally is vulnerable to blockading obstacles and enemies.
Sally gains a few stipulations akin to Knuckles in Sonic 2, for example, the ring quota in Special Stages are depleted and she retains her ring count after losing lives or entering starposts. 2 Player options (also with Sally replacing Sonic) and the ability to play as Tails remain from the original game however.