how about live tournaments, each player bets like 10 000 imps and winner takes all, or the prize is splited between first three players (tournaments could be 8, 16 and 32 players)
you should make all campaigns free because if you buy a new campaign there is a big chance that you will end up with less imperials than you started with, also should make possible replaying campaigns and make earning of imperials faster. + if you agree
 "Berserk: The Cataclysm"){kind=icon}
 "Distopix"){kind=icon}
 "The Button of AWESOMENESS"){kind=icon}
 "The World's Hardest Game #2"){kind=icon}
We plan to add more tournaments soon, thanks.