Our release of UBB uses the game's original control scheme.
The controls for Player 1 are:
W, E, R - jump up/left, jump up, jump up/right, respectively.
S, D - move left, move right.
Z, X, C - crouching block, crouch, sliding attack.
J - attack button (hold, or use in conjunction with the movement keys).
Player 2 uses the numeric keypad, and the Enter key.
If you wish to rebind your controls, you can use DOSBox's key mapper tool, by pressing Ctrl+F1, and change the keyboard layout in the game. This would make typing in high score names difficult, which is why we couldn't change the key mapping by default.