This is an excellent hack! I love it when new characters get the Sonic 1 treatment.
One little bug: Underwater, the air bubbles don't come from Vector's mouth! They come from where Sonic's head used to be.
And another thing, if you plan on making another character hack, let me list all those that have been done already, and to what extent they were completed:
Tails in Sonic 1 - Flying 100% similar to Sonic 3, Sprites Sonic 2'ed.
Knuckles in Sonic 1 - Gliding and Climbing present, Pallete issues fixed.
Amy in Sonic 1 - New moves with hammer, new sprites in style of Sonic CD Amy.
Eggman in Sonic 1 - Running animation and...thats it. Collision/gameplay were never finished.
Mighty in Sonic 1 - Gameplay, Chaotix moves, and sprites all here.
Vector in Sonic 1 - New moves, sprites, and even a few Chaotix moves!
Espio in Sonic 1 - Spin Dash now his Twister move ala Chaotix, sprites all here.
Motobug in Sonic 1 - Sprites, acceleration, and gameplay all altered.
Metal Sonic in Sonic 1 - Sprites the only thing changed, and not all of them at that!
Mecha Sonic in Sonic 1 - Sprites and Spindash present, Collision rewritten for larger character.
Sally Acorn in Sonic 1 - New moves, altered gameplay, and sprites!
Needlemouse in Sonic 1 - Sonic in his original form, with sprite changes!
And here are characters that were Genesized
but weren't in a strictly Sonic 1 Hack:
Shadow in Sonic Megamix
Chao in Project Shadow 2
Manic in Sonic 1: Brother Trouble
Sonia in The S Factor
Silver in the S Factor
Thats all I can find. Any more?