Unless the fighters are able to get into the air otherwise, it would probably be like shinzombie said, a boxing game. Doing away with the jump button means there are significantly less options to approach, which would in turn reduce the amount of options to defend against. It would be more or less a simplified fighting game where the neutral is rock-paper-scissors with approaching, blocking, and evading.

This kind of formula would be pretty good for an "easy to learn, hard to master" style game. However, it does also mean that depending on what you do with characters, the game will get stale after seeing the same situations and combos time after time. SamSho and SFV are good examples of this (I'm sure this is true for basically every fighting game, but those are the two that come to mind.)

I haven't actually played either of the two games to really make that connection, but I've seen enough gameplay of both to get a general sense of them.