BTS has it's own composed music too.
By the way, the
fucking composer for Sonic Team personally emailed the creator of the OST and praised it for how good it was. Yeah.
here's a sample:
https://www.youtube.com/watch?v=AuhwCEuV710
https://www.youtube.com/watch?v=1deuNknZqO8
In case you missed my post after that, I played BTS before it got an original OST. Also, I not care about the whole Sonic team thing, it's a matter of personal opinion, and personally, I love SRB2's music. Tempest Valley is dark and foreboding, Techno Hill is fun and up-beat, and Egg Rock is just plain great IMAO.
Anyway, I brought up the OSTs because of what I said: I played BTS when it's soundtrack was one big music rip from the world wide web. So, from the info I had, I thought BTS and ATS had unoriginal soundtracks (thus worse than SRB2's soundtrack in terms of effort and songs fitting to stages),but now I know better.
But seriously, I have played BTS, it felt like just another genesis game (not that that's bad: Sonic CD still stands as my favorite game of all time to this day).
SRB2, however, takes what it can from the Genesis games (aka what the Doom engine can handle, so no slopes as you pointed out) and adds new twists to them, such as since Sonic was always built for speed, but other than 3 and SA onwards he never had a jump ability, they gave him the thok. Or Tails, who can use his fly ability to explore the gelatinous slime of Techno Hill. Not to mention other original abilities to SRB2, such as the air drill, the Jump Boost, the Super Sonic hover ability, etc.
Also, please remember, this is the internet, so not everything needs to be taken 100% literally, like everyone is telling you when you keep quoting that one phrase you seem to keep bringing up over and over again.