It would be nice if we had sounds based on the following listed below.

1-When you draw a card of a specific entity it has a unique sound. E.g. Swordsman has sword sound when summoned.
2-Card Vs Card Sounds E.g. Swordsman fighting Wolf, you would hear Sword and Wolf attacks.
3-Unique Death sounds for each race. When human dies you hear human sounds or if you hear ghost you hear ghost sounds fading etc..
4-Environmental sounds. E.g. When you draw a Swordsman card you don't only hear his sword attacks but when first drawn you hear knights in armour in the background to bring it to life by the sound and you know it's a swordsman.
5-When low on health you hear heart beats.
6-Win/Loss sounds, If you win You hear a special win sound. For e.g. if you loose to a wolf you hear it chewing your heart out. or if you loose to a swordsman you hear your head cut off and so on for the other classes.
7-Special sounds for Heroes.

The way i focus on the above is pretending to play the game blind, what sounds would i hear ? can i guess what type of card it is without looking at the card.

Different sounds effect based on cards types like Ally/Ability/Artificat etc. Remember pretending to be blind and hearing unique sounds that you know what type it is without looking at the card.

Anyways hope this helps. Great game.