PDAmill has released Arvale for Palm. It was released for Pocket PC last year.
"Arvale: Journey of Illusion is an epic Role Playing Game, with over 20 hours of gameplay, six immense continents with 280 maps to explore, 200 different monsters to fight against, and over a hundred different items, weapons, and magic spells to use.
The current version is compatible with all current Pocket PCs and most Palm OS 5 devices and we're working on MS Smartphone and Symbian vesions, which will be available later this year."
Arvale costs $19.95. You can read our review of it here.