Since there was some more questions about score, I thought I'd clarify how it works in The Seal Hunter 1.2.
Let's start with some philosophy: What is a good game? What parameters should give a high score?
For example, should the score reflect progress in the game (as in "how far on level X did you make it before you died?"), or should it reflect how much money you earned and have left, or should it be mostly about keeping the enemies from even getting close to the right, or should it be more about making fancy kills with lots of headshots, lots of gibs, lots of multihit piercing bullets, lots of well-placed grenades, as opposed to general spam and holding the fire button?
As it is, it highly emphasizes lots of headshots (in quantity, not damage - so shotgun, rather than sniper rifle), keeping the enemies to the left (although this is relatively speaking more important in the early-game), gibs, and of course progress. It doesn't quite take into account the damage of each hit, so weapons with high damage per bullet (especially sniper rifle) do tend to give a bit lower scores since you get fewer hits and fewer headshots with those weapons. However, this is sort of counteracted by some of the bonuses described below.
If I recall correctly, the base score values for killing enemies are:
Brown Seal - 50
Activist - 70
White seal pup - 25
Penguin - 75
Fat seal - 150
Polar bear - 200
Turtle - 300 (500 if grenade-gibbed)
It also takes into account x-coordinate of death (from 212 to 0 depending on where on the screen the death occurs), and method of killing, as in:
A generic hit is worth 11 points
A headshot is worth 51 points
For hits, you also get a blood bonus, equivalent to 4*square root(damage of hit), for headshots this is equivalent to 4*square root(damage*3), so a headshot from the pistol would give 51 + 4*sqr(16*3), which amounts to about 79 points. For reference, a headshot with the AWP is worth about 300 points whereas a normal AWP hit is about 150 points, including blood bonuses.
Thus we can calculate the score of your little seal to 50 + 79*2 + XBonus, which gives a Xbonus of 4 at the far right, and 194 at the far left (take into account that the "true" x position may deviate a pixel or so from the actual centre of the seal graphics).
Certain enemies give lower scores (notably the fat white seals for which hits are worth 6 plus blood modifier). Certain weapons have different values for hits (magnum hits increase per level, and are at 25/125 on level 2 for example, and shotgun hits are worth less per pellet but the entire cascade does add upp quite a lot!). Piercing weapons give extra score from consecutive hits from the same bullet, and splash damage gives score as described above.
Gibs score higher:
Seal - 75
Activist - 100
Penguin - 200 (yeah!)
White pup - 50
They also give a bonus score which relates to animal type and level:
Seals give 120/80/60/48/40
Activists give -/100/75/60/50
Penguins give -/120/90/72/60
White pups give -/40/30/24/20
Splash damage weapons give multihit bonus (see cash value of that above), and score equal to 2.5x that bonus. The proximity bonus can be up to 100 points for a bulls-eye grenade hit.
A very high scoring event would be gibbing a seal on the far left on level 2, using the $2500 shotgun:
Blood bonuses -150 points
Hits - 70 points
X bonus - 200 points
Death - 75 points
Gib bonus - 80 points
Cash 8*10+5+50 = 135 points
This amounts to about 710 from a single seal, quite a bit more than the 212 you got from a far-right kill of a brown seal using 2x headshots with the pistol.
Oh, you also get 10000 for each completed level (including the boss, of course).
This is just scratching the surface of all the variables the scoring system takes into account but I hope it makes some sense.