Here is the full list of all 19 Red Risk achievements.
Survive ten tournaments.
Kill 2500 Infected.
Reach level 10.
Survive five tournaments.
Reach level 9.
Stay alive for 5000 seconds.
Kill 1000 Infected.
Reach level 8.
Stay alive for 2500 seconds.
Survive your first tournament.
Reach level 7.
Stay alive for 1000 seconds.
Reach level 6.
Kill 100 Infected.
Reach level 5.
Reach level 4.
Reach level 3.
Reach level 2.
Enter the arena.