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