I also got some suggestions, I only hope it does not cost Taxman to add these (Like in Xbox, where you have to pay to make updates etc)
I played Sonic 1, and got some ideas:
1. In Marble Garden zone, there are a lot of areas with a lava. I got a funky idea of using the fire shield to go into lava and find secret areas (Example, the place where lava starts to chase you when you drop down and run right. I was thinking "What if you can go into the lava and go to new places and secret areas?"
2. Using some unsused sprites for Sonic and adding them into the game
http://info.sonicret...edgehog_(16-bit)#Unused_Sonic_sprites
3. Adding Flickies to Super Tails
4. Challenges for the game, similar to 1 hack, such as have only 1 ring, beat level with 0 rings etc.
Those ideas popped into my head. I love that Sonic 1 so much, I usually never liked Sonic 1 before, cause to me it was a bit boring and cause Sonic 3 had lots of cool extras. But now Sonic 1 is like Sonic 3 to me, it went million times better <3.