User blog comment:SoCool21/BTD6 Ideas - Monkey Money/@comment-174.59.183.68-20120507221518

i miss glue! i like spike factory, and i think that pineapple present isn't enough. make a upgrade for spike tower that makes pineapple bombs and monkey glue come out, too!

P.S. if you don't like that, just make them separate towers. And 1, 2, Or all of them should have an ability that make nearby factories combined. has all the upgrades still.