SeaSim (DEU/ENG/FRA/NED)

EAT THE MOST FISH!
In the Sharks Sea, a lagoon at the Palantic Ocean, red and yellow sharks compete for the largest fish populations. Maneuver smartly and swim fast to eat the most fish!

(This is paraphrased from the publisher's site)
Both players are a type of sharks. You try to make your 'family' of 3 sharks (yellow or red sharks) the healthiest by having them hunt their desired type of fish (white, grey and brown fish). The goal is to attain a high health level, where health is the number of fish you ate less 1 (for the energy used to hunt). The populations of the 3 different types of fish grow during the game, so one needs to foresee and maneuver towards the larger fish populations to be in the right place at the right time.

Optional rules include a Virus that makes the fish sick (and adds no health to a shark), an Orca which competes with the shark to eat fish, and a Current which sweeps fish around the lagoon.