PopCap has just turned the page on a next chapter in its hit Bookworm game franchise. And that new chapter comes in the form of Bookworm Heroes.

Initially released in the Canadian App Store last December but now available internationally, Bookworm Heroes is essentially a turn-based version of PopCap’s popular word-forming puzzle game.

But its asynchronous social gaming feature, which converts formed words into attacks, is not the only notable departure of Bookworm Heroes from the original Bookworm.

For one thing, as in Letterpress, letters don’t have to be adjacent in order to form words in Bookworm Heroes. For another, Bookworm Heroes is freemium.

Bookworm Heroes

Furthermore, Bookworm Heroes is so named apparently because it features literary characters called Heroes, whom you can hire to boost your attacks against your opponents:

Get ready to rumble in an all-new test of vocab valor! Play for free and face off with friends as you build words from letter tiles and whomp foes. Hire literary Heroes to join in the fray and use their prodigious powers and special gems. The bigger the word, the badder the damage, so be sure to build the best word possible. Can you spell your way to victory in this vocabularious word challenge?

Bookworm Heroes lets you play against your Facebook friends or randomly selected opponents. And like most freemium games, Bookworm Heroes encourages you to earn coins, which you can use toward renting or buying new Heroes.

Compatible with iPhone, iPod touch, and iPad, Bookworm Heroes is available now in the App Store for free.