No. The gameplay is a mess for Saturn. Lower gravity and crazy changes in move restrictions. The game looks like it was developed with the same base code as MK3 for Windows and MK3 for PSX. The quality of the graphics and all the menus are identical.
UMK3 for Saturn has the new characters and levels and stuff added onto MK3 for PSX. But the changes to the gameplay were of the game-breaking type. I remember when I tried it getting standing HKs in the corner and getting jump kicks to juggle after them in the corner easily. Also there are just complete changes to the properties of some moves.
Comboing is easier, when move properties change they seem to be in favor of breaking the game. Overall, its an unfortunate hack of the game.