So, just today I remembered my dad bought sonic cd on the app store for me like 2 years ago, and I just now got around to playing it, and all I gotta say is HOLY CRAP! this is the first time I ever played sonic cd, and its super fun! I mean, the jumping sound effect is annoying to me and the zone 2 and 3 bosses are pieces of crap, but It's really fun just to sit down and play! that is all.

Aside from Sonic Heroes, Sonic Adventure DX, and some Sonic game I played the multiplayer mode of on a friend's Wii literally one time, I've never played a Sonic game that wasn't on the Genesis or SMS.

So aside from the ones I listed above (and a very small amount of them) I've played Sonic The Hedegehog, Sonic 2, Sonic 3, Sonic Spinball, Sonic 3D Blast (Genesis version), and Sonic Chaos. 3D Blast was easily my favorite though.
So yeah I'm completely clueless about Sonic CD. Is it a side scroller, or does it have 3D movement? And is it like basic get from point A to point B platformer stuff, or objective oriented?

Eirinn : well, while it is a get from point A to point B sonic game, this one does have a plot, and I'm going to give you the semi-quick version. basically sonic is on his way to visit little planet, which arrives to mobius once a year, but once he gets there he finds that robotnik has built a metal shell around it and tethered it to mobius by a giant chain so he can make it his base of operations, so he goes up the chain to defeat robotnik and save little planet.

The graphics are just like the genesis games except for sonic 3d blast for the genesis!

the gameplay is...well you can just play it casually but there are 2 endings as far as I know, the good ending, and the regular ending, the regular ending is achieved by just beating robotnik, and before I get to the good ending, let me explain the time travel segments.

These are completely optional but essential to get the good ending, basically throughout the levels you will see signs with future or past written on them, if you touch them and build up enough speed, you'll be sent the time period of the sign. the future is a horrible dystopian world where robotnik succeeded in conquering little planet, and the past is set before the beginning of the game, and your job is to find and destroy the roboticizer in each level, while this is optional, it is required to get the good ending, the other part of the good ending is to get all the gemstones at the end of the special stages.

there are multiple systems that have this game, but I'd honestly go for the 2011 ios rerelease, for a few reasons, one, you can switch between sonic 2 and 3 spindash and the sonic cd spindash, I recommend the genesis spindash because the cd one is a pain in the neck to get down, trust me! 2, the fmv's have been remastered to be much higher quality animation, and it now fits the entire screen! and three they've added an extra bonus, now if you beat the game once, you unlock tails and are able to play as him in story mode! plus this is the first appearance of metal sonic and amy rose, sorry if this was really long!

Sonic CD is one of the strongest entries in the series. There's multiple endings, different ways to experience each stage, and with the steam release you get to play as Tails. I have the game on steam, and it's one of my favorite Sonic games.

yoshirulez! : without a doubt one of the best ones in the series, I have to agree with you there!