Sonic the Hedgehog 2: Sonic 1 and 2

This is a hack for Sonic the Hedgehog 2 for Sega Genesis. It combines the levels of Sonic the Hedgehog and Sonic the Hedgehog 2 to make one large game. Special stages from both games are accessible and are entered via each game's special stage original entry method. This means Giant rings at the end of stages when retaining 50 rings in Sonic 1 and jumping into a circle of stars after passing checkpoints with enough rings in Sonic 2. There are 6 Chaos Emeralds in the Sonic 1 special stages and 7 in the Sonic 2 special stages. Super Sonic is not available until all Chaos Emeralds are obtained from both kinds of special stages. Progress is saved automatically to SRAM.

Pressing Start and the A button while playing any stage will return the player to the title screen. Also, level select is available by holding A button then pressing Start at the title screen.

Arena mode is playable which has time challenges that can be completed to increase the players ranking. Higher rankings are obtainable in harder levels and have shorter time limits.

Some features of this game were later incorporated in flamewing's http://www.romhacking.net/hacks/1038/ hack.

The patch is in xdelta format due to shifted data resulting in IPS patches containing original code. The ROM should be in BIN format.

Sonic 1 and 2

Credits: ColinC10

Sonic 1 and 2 is a hack of Sonic the Hedgehog 2 for the Sega Genesis. In addition to all Zones usually featured in Sonic the Hedgehog 2, this hack features all Zones from Sonic the Hedgehog (Sega Genesis), which have been ported, resulting in a continuous game experience from Green Hill Zone to Death Egg Zone. Both games' different kinds of Special Stages are available in all regular Acts, and they are accessed through their usual method (Giant Rings for Sonic 1, star post checkpoints for Sonic 2). The player must clear all Special Stages from each game, thus collecting Chaos Emeralds, 6 in Sonic 1 and 7 in Sonic 2, in order to become Super Sonic.

==Features==

*A full game of Sonic 1 and 2 starts in Green Hill Zone and ends as Sonic or Tails destroys and escapes from Death Egg Zone.
*Sonic 1?s Final Zone has been renamed to a second 3rd act of Scrap Brain (even though it is listed as Act 4 in Level Select) as it is obviously no longer the final zone. A normal act ending has been added to Final Zone just as if was any other zone. No ending is shown for Sonic 1; gameplay proceeds immediately to Emerald Hill Zone as though this battle with Robotnik were simply a normal boss battle.
*The Special Stages from Sonic 1 are available through Giant Rings at the end of every non-boss Act if the player has 50 rings. Also included are the special stages of Sonic 2. Star Post checkpoints in the Sonic 1 levels have been changed to those of Sonic 2, enabling entry to Sonic 2?s Special Stages in levels from either game if the player has enough rings when passing a checkpoint. The player needs all six Sonic 1 emeralds and all seven Sonic 2 emeralds to become Super Sonic.
*Progress is automatically saved to SRAM. It is possible to enable/disable this, or start a new game, from the options menu. Said menu also now enables the player to resume from the latest-accessed act with a different character or characters.
*It is possible to return to the title screen by pausing the game and pressing A
*The Level Select screen can be accessed by holding A at the title screen
*Arena Mode: Attempt to increase your rank by completing time attack challenges. Higher ranks mean harder levels and shorter time limits.

==Limitations==

*If both Sonic and Tails are on screen, and there are a large number of objects active, the framerate can drop somewhat. This is most noticeable in Sonic 1 levels, which is to be expected as the original game did not make any consideration of Tails and the consequent increased number of sprites.
*ColinC10 had to implement a lot of trickery to circumvent palette limitations, so some slight differences from the original games may be noticeable.

No-Intro Name: Sonic The Hedgehog 2 (World) (Rev A)
ROM/File SHA-1: 8BCA5DCEF1AF3E00098666FD892DC1C2A76333F9