In Vanquish for the PS3 and Xbox 360, you can unlock six different tactical challenges.
Tactical Challenge 1 – Complete Act 1 on normal or higher difficulty
Tactical Challenge 2 – Complete Act 2 on normal or higher difficulty
Tactical Challenge 3 – Complete Act 3 on normal or higher difficulty
Tactical Challenge 4 – Complete Act 4 on normal or higher difficulty
Tactical Challenge 5 – Complete Act 5 on normal or higher difficulty
Tactical Challenge 6 – Complete the first five tactical challenges