Achievements/Trophies

[Bloodshadow]

This may actually be a good idea, although I think the achievements should be easier, not something crazily hard like winning 100 PvP with full health or something.

The achievements/awards should be divided into categories: Bronze is the easy, Silver is challenging, Gold is hard, Platinum is for no-lifers, and the ultimate Diamond award...

And there should be some kind of reward for getting the achievements, like getting special cards and/or rares.

[Forfeit]

I like the idea but agree with bloodshadow  about some of your suggested achivments, and bankroller, no, well I think it would encourage more people to donate to the game, it makes it so not everything in the game can be gotten for free. Too many people would complain. Comeback kid, another no, same with mono and attrition. I like the idea of bronze, silver, gold. Maybe have a few that change like beat FG 50 times, bronze god killer medal, beat FG 100 times, silver god killer plaque, beat FG 150 times, gold god killer trophy.

[Spamalot]

How about a feature that would allow you to collect medals/ribbons for completing various challenges?

It's a pretty common feature to a lot of games, nowadays.  I wouldn't expect anything useful to be gained by completing the challenges, but it's fun to be able to say, "Yeah, I kicked Rainbow's ass 100 times."

Some quick ideas for challenges:

False God Nemesis:  one ribbon/medal for defeating each False God 100 times.
PvP Pro: After you fight 100 PvP battles, you keep this ribbon as long as your PvP win % stays above 90%.
PvP Master: Keep this ribbon until you lose a PvP battle.
Card Collector: Collect 6 of every card in the game (including shard of gratitude).
Uncle Moneybags: Reach 1,000,000 total electrum earned.
Flawless Victory: Humiliate (defeat without ever taking damage) your opponent in PvP 100 times.
Headhunter:  Defeat every player in the Top 50 in a Top50 match.  (Don't know if this would be feasible, given the fluctuation in the lower half of the Top 50.)
Mono-(Element) Master:  Win 100 PvP matches using a Mark of (Element) and only (Element) cards.
Comeback Kid: Win 100 matches with only 1 health remaining.
Blitzkrieg: Win 100 matches in less than 10 draws.
Attrition: Win 100 matches having drawn more than 100 times.
Bankroller: Donate $50 to the game.