Icarus
Phantasy Savior
I agree with you, I mean how many person who knows about SRB2 isn't aware of the tons of mods this game have?Personally, I'd rather see legacy content stay in the realm of addons, but I'm likely in the minority there.
Xmas stages should either be only available around the season (like in December only) like in Christmas Nights into Dreams.While we're discussing ancient stages that are in the game for no obvious reason, I also don't care for Christmas Chime.
I would even suggest to replace TLZ by the Xmas variation of Greenflower or use a SRB2 Xmas level if you really want to show how the game used to be in the firsts versions.