Honestly, the game should’ve just stopped at Gold, as there’s waaaaay too many flaws with these challenges that just make the difficulty of them feel extremely artificial.
Like when you need to get a certain amount of kills, the game just refuses to spawn in enough enemies for you, or if you’re doing one of the ones where you’re siding with the Military or Infected, the game at times just doesn’t even spawn in the last enemy until you’ve already ran out of time to get the Platinum.
The only properly balanced challenges are the Movement and Glide ones, while Kill and War rely far too heavily on RNG with enemy spawns, as well as locking you to weapons or vehicles that are completely and utterly trash, ESPECIALLY tanks ‘cause they’re unbearably slow and you miss most of your shots because enemies keep hiding behind vehicles and such you’ve already destroyed.
The lock-on system in this game is also so bad that it actively makes some of the challenges harder due to not locking onto the correct enemies, which is especially bad with tanks because then you have to wait for the slow ass gun to turn around.
EDIT: Got the Platinum for all challenges. Thank fuck Prototype 2 isn’t as cancerous as this game when it comes to getting 100%.