Scoreboards can track the kills of specific types of entities.
/scoreboard objectives add < name > stat.killEntity.* < display name >
This increases when you kill a mob of type *. The list of entity types that can go in * are:
Bat
, Blaze
, CaveSpider
, Chicken
, Cow
, Creeper
, Enderman
, Endermite
, EntityHorse
, Ghast
, Guardian
, LavaSlime
, MushroomCow
, Ozelot
, Pig
, PigZombie
, Rabbit
, Sheep
, Silverfish
, Skeleton
, Slime
, Spider
, Squid
, Villager
, Witch
, Wolf
, and Zombie
.
However, this method doesn't work if there are two enemies of the same type (2 zombies, 2 endermen). Note that spider is different than cave spider, zombie is different than zombie pigmen, and that skeleton is the same as wither skeleton.
To do the "point-giving" part:
Make an objective called points
(or whatever you want)
/scoreboard objectives add points dummy
Then, set it so that players can see it:
/scoreboard objectives setdisplay * points
Possible values of *
:
list
: Displays next to the player name when holding [tab]. (doesn't work in singleplayer)
sidebar
: Displays on the side of the screen.
belowName
: Displays under the player name (floating above head, doesn't work in singleplayer)
These all work when opened to LAN and more than one player is on.