This is another hack I discovered when trying to get to the Hidden Palace. It is possible to mix the code of one level with the code of another, so you get all the sprites and colors of one level on the 'floor plan' of another! Also, it works in Sonic 1, 2, 3, and S&K!
This is fairly complicated, so follow each instruction carefully (Please note this only seems to work with Genecyst)
1. Decide on the level you want the 'floor plan' of.
2. Use the level select and go to that level
3. When the name disappears, save a snapshot by pressing F5
4. Exit to DOS, and use a hex editor on the snap file.
5. Change the byte at address 0012280, offset 8 to any one of the
values in the following tables:
| 00 | Green Hill zone |
| 01 | Labyrinth zone |
| 02 | Marble zone |
| 03 | Star light zone |
| 04 | Spring yard zone |
| 05 | Scrap brain zone |
| 00 | Emerald Hill |
| 04 | Metropolis |
| 06 | Wing Fortress |
| 07 | Hill Top |
| 08 | Hidden Palace |
| 0A | Oil Ocean |
| 0B | Mystic Cave |
| 0C | Casino Night |
| 0D | Chemical Plant |
| 0E | Death Egg |
| 0F | Aquatic ruin |
| 10 | Sky chase |
The codes for Sonic 3 and S&K don't seem to be in a logical order. Just experiment! You can't harm the game or your system!
6. Exit the hex editor, and restart Genecyst
7. Press F7 to load the save game.
You should now have one level with the parallax and sprites of another!
NOTE: Some combinations will crash the game - press ALT+R to restart if this happens.