Spectromancer - Gathering of Power Walkthrough
About Game play:
You have your opponent both have a certain number of lives. There would be six slots where you can summon your card army. Each card will attack on the card which is in front of it. If there is not corresponding card the attack will damage the opponent. You can either summon a card or cast a spell. Spells are supporting units which make the game more interesting.
Use the in-game help book for more information about the cards, and different modes.
For achievement list, main menu> other option > achievements