Time Crisis 2 is one of my favorite arcade games... On this page you will find a few pics and some tips. I play this game with a friend so the tips wont be on solo missions and I'll only put up the Red players side sorry...
The best way to gain points is to finish each area as quick as possible...You will get a lot of points the faster you do it. When you shoot the enemies, you get 800 points if you hit them in the head, and 100 or so if you hit them anywhere else, and a few more hundred if you hit them a few more times. Shooting them in the head cuts down on time because the die right away and you get a lot of points for hitting the head. Through out the levels there are yellow clad enemies that give you 5000 points.