We could add something like that:
When a player succed any action below, a gold aura appears around him during 3 or 4 second:OR/ give some credit bonus/ medal you can see in the score board.
Kill 2 alien with a single shot of shotgun
Get 5 kill in a single lucy shot
kill 7 alien with an MD clip.
One clip a regular mara using rifle ( from 150 hp to 0 )
Chase a tyant in his base and kill him using blaster ( tugh life medal)
Stay in base the whole game ( by in base, I mean in RC range) => get a medal: "Use WASD"
Get 10 kills in tyrant in less than 7 seconds.
Kill a bsuit from 100 hp to 0 using a dretch
Get 3 sniping-kill in less than 8 seconds
Land 10 claw without missing any, in less than 10 seconds ( using mara)
other idea are welcome