Front Mission 5: Scars of War

Unlock hard mode:
Finish the game and save. After re-load a cleared saved game file.
The enemies will be stronger.

Completion bonus:
Finish the game then save when prompted. Re-load the cleared saved game file.
Now you can start a new game and play against harder opponents. All of your
previously earned character levels, skills, RP, CP, and Wanzers from your
original file will be remain.

Get Artassalt MG: Complete Simulator 2.
Get Special Machine Gun: Complete Simulator 2.
Get Glowtusk RF: Complete Simulator 5.
Get Vaje (body only): Complete Simulator 8.
Get Fuhjin GG: Complete Simulator 11.
Get Bee-11 BZ: Complete Simulator 14.
Get Goldias MS: Complete Simulator 17.
Get Special Missile Launcher: Complete Simulator 17.
Get Turbo BP: Complete Simulator 20.