I think some people said it ran faster on a DSi, but I'm not sure. If that is the case, SEGA was probably too embarrassed to put a sticker that says 'plays better on DSi' given how badly it runs on the regular DS units.

This is the most plausible theory if you do a little research and apply a little logic. There isn't enough power in the DS to run a software-scaled Genesis game at full tilt, which is why the best emulator at the moment pulls a number of tricks to use the DS' hardware rendering functions. You don't get to see the full screen all at once as a result, tiles are cut off in weird places, that sort of thing. Fully playable but a little funky.

From what I've found online, the Sonic Classic Collection seems to use an emulator with software rendering (it's suggested it was made by the same guy who created the above emulator, but based on his old software version) for the sake of full accuracy. The music is even apparently streamed, I guess, because there just isn't enough power. What this means for the DSi, though, is that if they include a DSi-mode binary on the card, then they get access to the faster processor, more RAM, etc. that has the potential to make it work better.

If anyone wanted to know, this IS indeed an emulation, not a real port. And it is also done by Lordus, the programmer of JenesisDS-

(IMG:http://img63.imageshack.us/img63/905/sccl.jpg)

Stephan Dittrich is Lordus, as you can tell from JenesisDS' official homepage.

Things i noticed so far-

- does indeed have some annoying lag, specifically in Sonic 3 and Sonic and Knuckles
- there are some sprite glitches in some rare places, things disappearing or garbling for a moment
- the music is separate from the games, as are the sound effects. They're streaming. We unpacked the rom to check
- tempo is really weird when speed shoes are used, kind of makes the pitch higher instead of faster
- the level selection works for sonic 1 and sonic and knuckles. S&K no longer pauses, so you need to get a game over to get back to the title screen and use the code. We don't know if the options in sonic 2 is still hidden somewhere.

It's not the first time they've done it though. Smash Pack games were coded by Steven Snake who programmed the best Genesis PC emulator, Fusion. The emulator they used for Smash Pack i believe was kgen or something. I think he did the Mega Collections as well, not sure. But they rarely use their own talent for making Sonic games.

And i'm sure they paid Lordus quite well. This explains why he disappeared mysteriously several years ago suddenly and never updated JenesisDS again. He was planning to improve it further. As it is, it's hard to tell what's better, this game or JenesisDS. On one hand, JenesisDS was faster and had what i'd consider "better" sound. And you could play in fullscreen. On the other hand, this version has less graphical glitches and you can play the lock on games. Decisions decisions...

Oh and since the music/sound effects are streaming in their own files, it could create a problem with injecting other roms. We'll see how it turns out.