It would be a memorale game.
But sadly it's not up to my expectations. I love to play hard games but only when I stand a fair chance. You throw us against foes that shoot too quickly once they come out and with 100% accuracy while we can't dodge the fires in any way. The credit thing is a good concept, reminiscent of an arcade shooter (Like Area 51 or Time Crisis). The concept of the one ammo reloading per button press is pointless, because all we have to do is spam the space bar so we get infinite ammo.
The graphics were all right, even though the characters were kinda stiff when they died or when they came out from their cover standing.
The sound was ok but a bit repetitive after a while of always hearing the same "Bam" sound each time we fired or the same gasping sound of the baddies that we slaughter.
As for the difficulty, it matters a lot. Because if the game is not pleasant to play, we won't like it. It's obvious why you can play the whole level without losing a life : Because you know the level by heart, you made it!
The violence was moderate since there was no blood or gore whatsoever but still there was some shooting.
Some humor a bit, when hostages beg for their life but you still shoot them by mistake.
Overall it's a pretty good game with great programming, but it lacks in enjoyability.