In mechanics it’s pretty simple, there’s the battlefield, there are mana crystals that you put on the field of minions and use abilities.
Minions can deal damage in melee or ranged combat, depending on the creature type.
Your creatures can have the following properties
Ability – Can do something for X mana once per turn.
Bloodtoll – An additional cost that MUST be paid for play the card
Bounce – Return to it’s owner hand
Charm – Forces a unit to move towards the charming a unit or tile
Charge – Can attack and move on this turn it is summoned
Choose one – Choose one of the available features
Damage Shield – Blocks the first damage dealt against this unit
Deepstrike – Can be summoned to any location on the battlefield
Deathhowl – Does something when it dies
Exile – Removed from the game. Prevents Deathhowls and doesn’t enter the graveyard
Fear – Forces a unit to move away from the fearing unit or tile
Flying – Can move to any location on the battlefield
Loyalty – Does something when next to your hero
Poison – After this unit deals damage to a minion, destroy that minion
Root – Cannot move
Splash – Also damages all enemies next to whomever it attacks on its turn
Stun – Cannot attack, conterattack, move, activate triggered effects, or use abilities
Supremacy – Does something when on High Ground
Uncontrollable – Not controlled by anyone, run from these as far as possible
Upgrade – May choose to pay extra mana to gain ONE of the upgrade options
Warcry – Does something when you play it from your hand