Did this game just fly right by everyone's radar? Made by the same team that made Henry Hatsworth, another amazing game you need to own. Picked this up on a friend's recommendation. So good. Here's the story:
You play as Ellie, a young girl who gets magically warped to a different world. Upon arriving, she finds an egg which hatches into a monster, which Ellie names Chomp.
The game plays a combination of Metroid, Henry Hatsworth, and any RPG with a skill tree system. Metroid style maps and areas that are blocked off until you have the skill to proceed. The combat is HH style, a melee attack with a launcher, and a combo system that smashes out better rewards for a higher combo count. Sometimes enemies drop items like cookies, barbells, scrolls, soccer balls, and so on. Chomp can move between the two screens, the top one to fight with you and the bottom one to eat the items you've found.
Chomp can consume items on the lower screen to gain experience and stats. After a while, he'll level-up gaining newer stats and stuff. Eventually, you can evolve him into different forms (based on fire, water, and leafs with the expected strength->weaknesses). You can also move Chomp between evolutions to best suit the situation. Any abilities and skills he masters in one form can be used in other forms.
Anyways, hopefully you've read this and are willing to give the game a shot. You'll probably be just as surprised at the quality of the game as I was. Give it a shot.
Here's a quick gameplay video:
http://www.youtube.com/watch?v=z4gLleFUa0k