A couple of things I think really should be added.
- Reset Button: Bad starts are annoying as hell. And when you're on the back foot from the start in a game where cards can PERMANENTLY snowball, it's annoying to sit through the game. Especially when running this in the browser.
- Remove permanent snowballs: Seriously, once one of those gets out of hand, if it's not yours you lose. Also vastly defeats the purpose of any strategy if RNG gives you one of those early.
- A little more variety in leaders.
- Being able to move cards from field to bench.
- More rebalancing in general.
The permanent snowballers were a massive outlier since there's no way to deal with them.
EDIT: Okay, I've run a few more rounds. Things are clicking more. If infinites are gonna be the general style, it still needs some rebalancing. And more effects should be added to help deal with or support them. Like "taunt" that makes a target a priority or other things along those lines.
Although since you've mentioned that the game is complete... I'll settle for a reset button.