You're right on the money with this feedback. The different blood types have a stat sheet that effects the resulting projectile and none of that is comunicated in game. We've gotten many simmilar comments to this and it's one of the first things we want to improve if we decide to keep working on polishing and expanding this current gameplay loop. The wave system is much more PvZ than CoDZ, it's just on a timer and the idea was that to not be overwhelmed in later waves you'd need to be efficient in clearing out all rooms on the map. Maybe this wasn't the greatest approach and I'll absolutely share your thoughts with the team.