Well, since we're making Metal Slug now, here's some infos:

Heavy Machine Gun (H)
-start with 200 ammo when acquired
-add 100 ammo if you're "reloading"
-1000 points
-Machine Gun that spreads vertically a bit. dmg is equivalent to 1~1.2 of handgun

Rocket Launcher (R)
-Start with 40 ammo if I'm not mistaken
-add 20 ammo if you're reloading
-1000 points
-It's like a rocket. it slows a bit and first and it launches horizontally. can shoot up to 2 per screen, and does splash damage

Shotgun(S)
-40 ammos
-add 20 ammos when recharging
-1000 points
-Shotgun. It looks like triangular explosion when used. Serious damage (I will say about 50 times handgun?) Have some reload delay.

Flame Shot(F)
-40 ammos
-add 20 ammos when recharging
-1000 points
-Flame thrower that spits some flames. short range, but powerful.

Laser Gun(L)
-200 ammos
-100 when recharging
-1000 points
-penetrates infantry. 1 ammo per frame.

More Info soon

General character info
-player can run/jump while shooting.
-player can aim side, up, and down(when jumping)
-when enemy is closed and it's infantry, player uses knife.
-each successful hit with gun is 100 points, and each successful hit with knife is 500 points.

Enemy info (1)
General Infantry

Grenader
-Just hang around until it detects the player.
-throws grenade in parabolic motion, aimed at player.
-1-hit kill

Shielder
-He have shield that can take about 15~20 handgun bullets.
-when shield is gone, he attempts to run away
-shoots gun behind shield
-shield is 1-hit against knife

Bazooka
-He shoots bazooka that's kinda slow
-Delay is until the bullet runs out of screen/hits something
-1-hit kill

It's good.
So what's the title name?
Also, I'm working on the tank sprite(the one that we can ride), and I'll post it soon.
EDIT: for the sake of game size, I'll not make the vulcan cannon aimable.(at least, graphically )

bazooka guys usually doesn't move
He just sits around in the specific position (except for paratroopers, but I don't think we'll gonna include that.)

I'll give you the link of the shield guy asap.

Here: http://sdb.drshnaps.com/display.php?object=5371
Don't do aiming up/down thingy.
Shooting is the must, but the sword strike is optional for you

do what you want to do.
Personally, I wouldn't make the soldier hold grenade.
The sprite is just too small for it imo.

Here's the sprite for metal slug(tank) (16x16)
for shield guy, make him hold just a shield. just draw the gun only when he's shooting.

2nd sprite is crouching, and 3rd one can be fire cannon/hit

The shield guy looks great.
However, you should try to make shield more rectangular.