4/5, and let me explain why. This is truly a good game; great graphics, great gameplay, and a great storyline. The fact that one must pay to continue past the demo has no effect on the rating. Paying does not help you get the badge faster; it exists as an *option*, not a requirement. And paying for a game says as much as a Thank-You card to the Developer.
Requiring someone to wait for 3 minutes to regenerate 1 energy which allows them to move *once*, then offering to regenerate all their energy for a small amount of money is insane. 1/5
2/5, and here's why: Each level up in difficulty means damage bonuses for the enemy. There is no change in skill and the attacks are to the point where a War-Machine can be taken down by a single commando.