Yeah the first one is good, the second and third, urgh, hate 'em. Tho' that opinion is pretty much based on the fact I can get through 1 (Albeit with Save Stating, but still, I did it), but 2 and 3 seem to screw me over round Zone 3, that disk boss on number 2 is probably my least favourite boss of all the bosses I've fought in the sonic series.
On the thing of homing attack, I think it's best place is in the 3D Sonics, I don't think I could really get through them without it, as hitting enemies without it is a nightmare. For the 2D one's it's not really needed, as it's fairly easy to hit the enemies when all they can do is dodge in a 2D Plane, plus the controls are generally better.
As for this game, I'll probably end up getting it when all the parts are out, because unless the episodes are fairly long then there won't be much point in getting 'em.