More Buck for Your Bang
In game design, there’s a concept called “First Order Optimal Strategy” which is used to describe any set of moves, tactics, or particular strategies that are inherently more powerful than they are difficult to execute. Examples of this include Ken’s uppercut combos in Street Fighter IV, particular button mashing patterns in games like God of War, or the n00b tube in Call of Duty. Most shooters are able to avoid this because the gameplay doesn’t usually quantify the way you kill your foes, but Killzone: Mercenary does through its bankroll system and thus the player will always seek to maximize their killing methods.
During my own play through of two of the single-player levels it became obvious that melee kills offered a great deal more cash incentive when compared to just shooting the bad guys. This naturally led to a desire to stealth-kill pretty much everyone I came across because it provided the most money for the least effort. While the developers I talked to insisted that it would be possible to earn more impressive payouts with grenade multi-kills or environmental attacks, neither of those options seemed to offer enough of a payout to make the extra effort worthwhile.
It’s near impossible to find a perfect balance between skill of execution and value of payout and because of this Killzone: Mercenary will always suffer from the effects of “First Order Optimal Strategy” syndrome. This becomes frustrating when much of the game revolves around earning as much money as you can and the method of doing this goes against the mode of play you wish to employ. Regardless of how they manage to iron this out, it’s hard to foresee this issue ever being completely resolved.