Sonic was revolutionary when it came out. Previous to that was Super Mario Bros. which compared to Sonic was lame and boxy. The things I liked about the early Sonic games were the music and the graphics which were pretty cool especially when you were moving at mach 10 speeds!
They're quite different and certainly enjoyable games. My friend Maxine couldn't defeat one boss on the first D.S. sonic game, and I tried for her. I was the first to jump over this sliding thing twice. When it got to three then four times, I was worried. But I did it. Ho yes! 
