Step 1: Movement

Whether or not our character can move is irrelevant, but, we roll in style. The following events will move and animate the player while holding one (but not both) arrow keys. Note we are only moving the legs.
Next, play the Stopped animation when the player stops moving or presses both keys at once. Note that pressing both arrow keys with the default platform movement will make the player move left. This never happens in any "real game" and it instantly makes your work unprofessional.
Alright, so test your game and you will see a pair of legs running around. Something is definitely missing. To complete the body, simply Always position the Torso at the location of the Legs.
Nice work. The next step is to make the player fire his weapon.
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