Yeah, you only start out with a pomeranian and a sika deer. You have to defeat a "boss" animal to unlock a new animal to play as (IE:You fight a boss lion, you unlock a lion) which I think is only available if you've been alive for 30 in-game years or so. I believe ever in-game year is a one minute and you can live for up to 120 years if you keep changing generations so the real challenge is surviving survival mode for 1-2 hours