Hi Mauro, I just wanted to say I wish you all the luck on this, I am the biggest SF1 fan out there, I know the game inside out more than anyone,...and I even dare say more than the programmers of the arcade original, and would also be happy to be a playtester for you on this project in you need someone.
Back in the day (early 1988) everyone was waiting in line to play this at our local arcade (6-buton version), I mastered it quite quickly to the point I used to get watchers to tell me to what move to perform and when just to prove I could do the special moves and it wasn't down to luck, I even own the actual 6-button arcade machine which sits in my living room from 1991 when I bought it.
I hated SF2, it too easy like all the spin-offs and sequels (completed on my 3rd go,...felt very disappointed), too slow, crap tunes and Sagat was a puppy in it compared to his killer side in SF1, I just found it so boring whereas the actual arcade machine of SF1 (not the choppy ugly uploads on the internet) ran so quick, great tunes and it had a killer instinct/sudden death feel about it,...at a blink of an eye a round could be lost if you didn't know the special moves especially at the hands of Birdie, Eagle or Sagat.
I really hope you see this Megadrive version through to the end, by the looks of it you're doing a great job so ignore the SF1 haters mate, there are a large amount of us SF1 arcade fans out there that learnt how to play this game back in 1988 and not start off playing the easier slower sequel, so this project is certainly interesting to us.
Can I just ask Mauro, if you plan to hopefully make it as close to the arcade original as possible, why have you changed the energy bars and timer?! please make them the same as the original please, also I hope you plan to redo the music as I have to be honest it sounds terrible for the Megadrive sound chip, very tinny and weak compared to the arcade original.
Feel free to contact me for any advice on the game or help playtesting it :-D