Sonic the Hedgehog 2 Beta 6 for the Sega Mega Drive/Genesis was released by drx during the February 23rd, 2008 proto release. It is also known as S2BETA6. There seem to be two versions of Beta 6; but aside from a couple bytes in the header they're identical, byte-for-byte.
- Level Select code: , , , , , , highlight 1 player, then press + .
- Debug code: , , , , , , , , , , , , highlight 1 player, then press + .
- Level select is still similar to that of Sonic 1 in this build. The level select menu appears behind Sonic and Tails, and Sonic is all black. This is because, as JoseTB explained, "the first line [of the title screen palette] was the background in previous builds, but it's used by sonic in the new title screen. Of course, the level select palette remained untouched with the change."
- The title screen is identical to the final, but the trademark symbol is white instead of yellow.
- Appears to be the first prototype with the options selection.
- "Sonic and "Tails" in" (or "Sonic and Miles," depending on region)
- The special stages remain the same, except with a palette change.
- As in Sonic the Hedgehog 2 (beta 4) and Sonic the Hedgehog 2 (beta 5), the player can run right past Robotnik in Death Egg.
- The final boss only takes one hit, most likely to facilitate testing of the newly-programmed full ending. In previous builds, Sonic and Tails just fly off to the right.
- Super Sonic's ending is not implemented, Sonic's regular ending is used instead.
- Tails' ending is not implemented; he uses Sonic's.
- The Sonic 1 style spike behavior has been changed.
- The "You got a Chaos Emerald!" screen is glitchy.
- The collision detection in Emerald Hill Zone is a bit wonky in some places.
- If you complete Wing Fortress Zone as Super Sonic, you'll end up jumping over Tails' plane, and fall to your death.
- When Super Sonic clears a level he will not go back to normal Sonic and the ring counter will still continue to drain until it hits zero.
- If Sonic breaks an invincibility monitor and goes Super he will have the invincibility stars. This bug is also in the final.