Suggestion, Defence Events
Not much of a suggestions (I assumed some interesting new mechanics). But yes this seems like a good enough idea. The only problem of course is that you’re giving the stick without the carrot in sight. This system is intended to only punish players for succeeding, without benefit to them. Usually you’d give them better rewards the more ‘levels’ they’re able to defend through.
Give a pretty nice chest after each wave, make it server only for contests, make it group/guild content with leaderboards…
“Ash nazg durbatulûk, ash nazg gimbatul, ash nazg thrakatulûk agh burzum-ishi krimpatul”