Scratch

Well I'm trying to make a 2 player (1 sprite per player) sword-fighting game, but I've run into a problem,

Only 1 Sprite can move at a time, and if a sprite starts moving while another is moving the one that was moving first stops.

I've made it like this:

When (right) key pressed
point in direction 90
if on edge, bounce
move -3 steps
If (Color gray is touching gray)
   set instrument to 128
   play note 60 for 0.1 beats

"(right)" is the key assigned to a sprite for moving right, in this case the sprite on the left (Sprite1) is 'd'. For the sprite on the right (Sprite3) it is the 'right arrow' key, however depending on the sprite the move -3 steps could be either move 3 or move -3. The sprites are set so that they only change direction, not completely rotate around. They are the same sprite but the one on the right is flipped to face the one on the left.

The gray touching gray is so that it makes a little noise whenever the Sprite's swords touch, and it works fine. I'm also thinking of making it so that when they touch the Sprites move away from each other a step or two, and making key presses to perform moves like a fast stab (moves like 20 steps or something?) then has a wait 1 sec and then moves back maybe 15 steps.

I need to understand why it is that only 1 sprite can move at a time like that. My friend David made a PacMan where it is 5 players, meaning 4 people can control 4 ghosties and 1 person controls the PacMan, and the goal of the PacMan is to stay alive. It even has a background for it that looks like the real PacMan, but w/o dots (since that isn't the point of the game, the point of this one is to just stay alive) and they actually will stop if they hit a 'wall' in the background. Each character can be controlled by a different set of 4 keys acting like arrow keys like how I have mine set up. I don't see why mine doesn't work like his.