Ah, the ORIGINAL Capcom vs. SNK game... With CVS2 existing, it admittedly makes the initial game feel rather lackluster, but CVS1PRO, the updated re-release of the original game still has it's own shine that the sequel doesn't. While the USA version was on the PS1, I'm taking the time to play this on the Japanese only Dreamcast due to better graphical and loading fidelity.
Of the many differences is it's controls, taking more of a page from the SNK side and being a 4-button fighter instead of 6 (meaning many Capcom characters had their medium and heavy normals on separate D-pad commands), the fact there were only 1 fighting groove per company, having to select either run or dash from the main menu instead of being baked into a groove, and the character ratios being set instead of free-form. Oh, and the ability to have a team of 4 Ratio-1s was a thing only in this game. Luckily, UNLIKE the original game, all the stages and characters (including EX character) are unlocked from the jump, as well as adding Dan Hibiki & Joe Higashi to the cast. While the SNK side obviously got all new spritework, this was still Capcom reusing assets to make their games from their side, mainly using Alpha spites for the SF characters (even Chun-Li in this game, unlike the new sprite sheet she'd get in CVS2 based off of her Third Strike appearance).