Like trying to feed a Tribble.
You can play as either the guy or the girl, but it doesn't really matter. Your partner will be a bottomless pit constantly whining about being hungry, or thirsty, or tired. And they're completely incompetent, only drinking or eating when you tell them to (although later in the game, they'll drink bottled water by themselves, thank goodness). And they do absolutely nothing except throw some logs on the fire. You can ask them to cook, if you want burned food.
So apart from a totally idiotic loser hanging on to you, the game isn't so bad. You pick mushrooms and shake coconuts off trees, fight wild animals and build furniture for your cave (or treehouse). But still, the hungry hungry partner is always there, always whining.
The game has multiple endings to choose from. Personally, I'd prefer the ending they didn't include - impaling my partner's head on a stake, ala Wilson the Volleyball.