SNES Dracula X was 16 meg I believe, which is only 2 megabytes, nothing compared to a CD. Also, for whatever reason Konami chose to go a different route rather than make a straight port of Rondo. Looking at the sprites it's obvious that the SNES could've handled a straight port had they had the space. Rondo is not a game that couldn't have been done on the SNES had it had a CD attachment.
Rondo is about 16-18megabits total (well, excluding cinemas). The SNES has enough space. Not only that, but the SNES has 128k of work ram; they could have been used for even better compression schemes because of its size. Space wasn't the issue.
I think you're waaaaay off here. Rondo has two data tracks on the disk apart from the audio tracks. Both of those data tracks are around 20 megaBYTES each. Not megaBITS, megaBYTES. So, you're comparing Castlevania IV and Dracula X SNES which are 1 and 2 megabytes to Rondo which is 40 megabytes. Yes, some of that is for cinemas but not that much. Rondo could NOT have been done on a 20 megabit huey minus the cinemas and music.
Look, I'm not trying to be an ass - but I actually
looked into this game. And I'm the one that did the print and compression routines for it PCECD Dracula X translation project (including the title screen). I know bit about this game on a technical level. I was looking for secret stages in the ISO, based on all the CD read commands and tracked all the LBA/sector offsets (I found part of one, but not the rest of it). There is a lot of redundant data loaded each level. So while each level might load <2megabits, there's redundant data in those loads (tiles and sprites) across the level layouts. You can't simply look at data track/iso, and say that's what the game requires. There are huge gaps in the data track that aren't used (this is VERY common for PCECD games). And the second data track is there for redundant reasons ~only~. It's the same track
I'm go by Bonknuts here, but I'm tomaitheous elsewhere (in relation to coding). If you don't want to take my word for it, then take a look for yourself in a debugger.