I've picked up playing Rise of Atlantis (Premium) [ROA] on my iPad. It is a sequel to Call of Atlantis [COA] that I've been playing on my iPhone. I enjoyed COA so I definitely would enjoy ROA. ROA is the same gameplay as COA. So I really don't have to explain it again.
1. Relics - There are more pieces of relic to find. The final piece you are collecting is bigger. COA you finish a piece after each game. You tally all the relics at the end of each land to complete a room with the missing relics. In ROA, you get pieces of at each game in the land you are in. The last game in the land completes the relic and it stores the power in an alter similar to COA.
2. Aesthetics - The graphics are a bit better than COA. That moved things around and gave them better animation since there is more space on the iPad screen.
All in all it's same game with with a slightly changed story. You visit the same lands as in COA.
You can find Rise of Atlantis in the iTunes App Store for $4.99.
[iOS]