When you play Minecraft on multiplayer, a large part of the experience is defending your items and PVPing with others. However, this becomes slightly repetitive if the only move you can do is spank your enemies with your sword. When you climb ladders or swim, your character looks kind of retarded bobbing up and down without moving your arms or legs in any way. So this is my proposal:

Swimming
- Arm and leg motions when swimming
- Water dripping when you exit

Climbing
- Arm and leg movements
- swaying back and forth as you go up each rung

Attacking (Fist)
- Use both arms
- Two or three different animations

Attacking (Tool)
- Use different types of hits
- Combo attacks (optional)
- Final Blow
- Different Sounds depending on mob, type of tool (wood, stone, iron, etc.), or armor

If you use your minds, you can think of many more. These are just a few examples i think are most important. I think that by doing this you will improve the game play of minecraft. Please consider my proposal. Thank-You!