Cycles
Many of these motions, such as the runs and walks, are cycled motions. Much of the screen time for your characters will be spent in cycles. Learning how to make a cycle that doesn't look like a cycle is an essential skill to learn.
A cycle for a game is fairly easy to create but a bit more difficult to get perfect. The key is to duplicate the first frame of the cycle to the frame after the end of the cycle, to make sure that everything syncs up. After that, the various motions of the character are offset so that their cycles don't all repeat on the same frame. This will make your character look much more lifelike and natural.
Most cycles are animated as though the character is walking on a treadmill. This means that the feet are not locked to a fixed point in space, as with most walks. Instead, the feet slide along the floor at a constant rate. This rate also determines how fast the character moves through the game, which should be communicated to the programmer.