system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the "gamey" flavor of wild meat?
gpt
The gamey flavor in certain meats can be due to various reasons.  It usually is attributed to fats and fatty acids, the animal's diet, muscle use, sex hormones, exsanguination procedures utilized, and carcass handling.

Many of our domesticated animal species are fed out on grain based/corn diets, which changes the flavor of the meat.  Most wild species are not going to be grainfed, or even strictly pasture grassfed.They're going to have consumed whatever greenery is available, safe, and palatable to them.  It could be various grasses, weeds, leaves/pine needles, in some cases various insects or carcasses of other animals.  Whatever they eat is going to influence the taste of meat and milk.  For example, if they eat a significant amount of wild onion or similar strong plants, there will be an oniony taint to the milk and meat.  Even grassfed vs. grain fattened domesticated animals are going to have at least moderate differences in taste due to diet intake.  Corn and grains usually produce a more sweeter to neutral taste than grassfed does, which is often stronger and more earthy tasting.

Additionally, even between domesticated species, there are differences between the fatty acids/fat compounds that are present, which also influences taste.  This is one example which applies to why lamb has a more gamey flavor than beef typically does, raised in similar feed out scenarios.  This is why in certain cases removing any excess fat off meat cuts from wild animals, will reduce the gamey flavor which is often most prevalent in the fat and fatty tissues ("marbling" in domestic animals).

Muscle that is more often utilized is going to have less fat, will be tougher due to use than cuts of meat which are in less or unused areas of the body (abdomen, flanks, buttocks, etc...), and can be more acidic depending on the extent of activity and time of butcher/hunt.  There will be a difference in animals that have had more activity/exercise than those who have a more leisurely lifestyle.

Hormones can taint the flavor of the meat as well.  Intact male animals usually have a stronger tasting meat than females or those who have been castrated, particularly before sexual maturity.  Boar taint is an example of this, where intact male hogs (boars) produce meat which can be unpleasant in smell and taste versus the pork products derived from female hogs or males which have been castrated or not reached sexual maturity.  Testosterone causes stronger flavors and smells than does estrogen.

Lastly, if the carcass has not been properly drained of blood and other fluids, it will impact the taste.  As will improper handling of the carcass, especially if internal organs are accidentally opened during the process and contaminate the meat.

Edited to add, because a couple of people have asked, exsanguination just means the way that the blood is removed from the animal's body.  Depending whether it is done when the animal is dead (no heartbeat) or stunned (unconscious and/or vegetative state with heartbeat), can have some impact on the efficiency, especially if someone is a beginner or is limited in resources (cannot effectively elevate the carcass for appropriate drainage).