It's the first time I'm playing Sonic CD and, well, what can I say? I don't really like it.
I don't like the level design very much. The levels are too huge and messy, to a degree that I'm feeling lost most of the time and that prevents me from enjoying the experience very much. It all just seems very random and hard to memorize. This wouldn't be nearly as much of a problem if the game had somekind of auto-map feature but, well, it hasn't. I also really hate it how enemies sometimes blend into the background too much and are thus hard to see. There are also way too many boost-thingies that just send you straight into an obstacle. Where's the fun in that? That just frustratingly bad design.
The time-warping feature is awesome in theory. In practice it's not much more than a gimmick. And I don't think a very fun one. It's purely optional, and even if one wants to search for the signs, search for a space in the level where you can reach full-speed and then find one of these damn generators, it just doesn't feel very revarding -- and doing it in every level is just frustratingly hard, especially because there is no real benefit from playing that way. It's like this feature is just for the hardcore Sonic fans :| Honestly, there's so much cool stuff that they could have made with time traveling, and instead they couldn't do anything else than a lame search quest. Again, it would have been more fun if the game gave you a world map, so that you could replay levels again. And why is there that stupid time limit of 10 minutes?
It's not like I'm not enjoying the game, and I'm sure that there's a really great game hidden somewhere, but I just can't see it. I don't "get" the game.