At one point in PSN exclusive Tokyo Jungle, I was playing as a gazelle sneaking past a group of hungry velociraptors by hiding in a box, Solid Snake-style. It's a ridiculous moment that perfectly exemplifies the experience you'll have with the game, but the fanciful trappings disguise challenging gameplay that combines stealth and strategy elements to create something strange and addicting.
Tokyo Jungle takes place after humanity has vanished, leaving the pets, zoo beasts, and wild animals to scrounge as best they can for food. In Survival Mode, where you'll spend the most time, you play as an assortment of creatures, both carnivores and herbivores, leading them through different Tokyo neighborhoods in a bid to extend your bloodline through as many years as possible. You will face many enemies as you prowl the streets and rooftops, everything from hyenas to crocodiles to silky terriers (don't laugh, when those things gang up they are wicked mean), but your greatest enemy is the ever-present hunger that gnaws at your belly. To keep it from chipping away at your life meter, you'll have to stay full by constantly seeking out your next meal, which is where the core challenge of Tokyo Jungle lies.
You'll navigate the streets of Tokyo in search of nutritious plants if you're a grazer, or other animals if you're a predator. Though occasionally you'll find a carcass just waiting for you, in most cases you'll have to bring down your prey by attacking them first, with either a sneak assault or an up front paw to the face. The collision detection can be a bit iffy, but for the most part the combat is swift and satisfying. The supply of food waxes and wanes from neighborhood to neighborhood as time passes, and if you find yourself stuck in a barren part of town, you'll have to move on to new territory. Disease and smog roll through areas regularly, potentially poisoning available food sources or just raising your personal toxicity level, adding another drain on your physical resources. Some neighborhoods can be run through quickly, but others are massive, sprawling affairs requiring deft navigation - if you're slow and hungry, simply getting across a toxic part of town can spell your demise.
Eating not only keeps you alive, it also helps you level up and become more appealing to potential mates. Shagging the desperate retriever might seem like a good idea at the time, but the better your mate, the better stats you'll pass along to your offspring, thus increasing your bloodline's overall chances of survival. Beggars can't always be choosers, however, especially if you're rushing to complete one of Tokyo Jungle's many challenges. Each time you play in Survival Mode, you'll be given a new set of challenges to complete, such as eating a certain number of kilocalories, changing generations (mating) a proscribed number of times, or finding a specific geographic location. You only have so many years to finish each challenge, but ticking them off will net you Survival Points and stat-boosting items like hats and scarves.