Glu needs to allow users to play different shooter games while taking their weapons, armor, etc with them.
You want a lot of people playing Last Day Alive? Allow a user who has already spent the time/money in rival fire to bring their weapons and character attributes to LDA. Same with Deer Hunter. Users should be able to move from game to game. It's really not that difficult to determine how a weapon in one will transfer to the next (power, accuracy, costs, etc). You could either allow the same gun to played in all games or swap for a weapon with "equivalent" attributes in the another game.
I would be so much more likely to spend $$ and time playing all Glu shooter games if I didnt have to start over rebuilding my cache of weapons, armor, etc. I used to play what is now DH Classic. As soon as new the DH was released and I had to start over, I quite playing DH altogether.
I have invested a lot of time and money in rival fire. LDA is soon to be released and I probably wont play. I just don't want to start over. Too much time, effort and money.