That's pretty cool. Idea of tower defense and using card as the monster is nice. You should release the game with more levels and graphics.

It was fun but unclear what the benefits were for summoning stronger units early on.

A cool choice for the theme reminds me of bloons battles where you have to send enemies to your opponent's base. I do wish there was a wave-spawning timer. I did not really get why me units came out or not until I read they were spawned in intervals in the description. 

This is a fun twist on the TD genre!
I think the balancing could be improved, e.g. there was no point for me to start with a spider instead of 2 rats because the units drop the same amount of gold.
Nonetheless a very enjoyable somewhat idle game, good job!

Really nice game!

The game design and the whole concept was really nice and the game was smooth.

I won only using mice for gold farming, 2 witches for attack and 2slimes for tanking.

I really enjoyed it, well done!