Press the green flag and enjoy! (Note: The music is quite loud, so you may have to turn down your volume.)
You break it, I fix it. I added a fade-in, changed the background to the correct one (people just assume it's Green Hill, but the title screen has darker water.), fixed the background's awkward scrolling, added the (C) SEGA 1991 text, and corrected the sizes of all sprites to closer emulate the original game.