Sonic the Hedgehog Plus (often called Sonic 1 Plus) is a hack of Sonic the Hedgehog by Hivebrain. The hack is basically the same as the original game, except with a number of extra features and bugfixes.
- Green Hill Zone (act 4) - a new act has been inserted between acts 2 and 3 (so that the last act ends with the boss).
- Marble Zone (act 4)
Other new things
- Spin Dash
- Expanded level select
- Title screen updated
- Sound Test and Options menu
- Turn Spin Dash on/off
- Change number of lives you start with to 1, 3 or 5
- Press in debug mode for shields
- Bugfix - Green Hill Zone tunnel death
- Bugfix - double spike death (by drx)
- Bugfix - wrong animation when jumping next to a solid object (by Stealth)
- Bugfix - "Broken" Marble Zone pillars have been fixed