AH! perhaps rewording it would help then! :)
i'm not native american, can you show me how my sentence would be correct
Its not exactly incorrect - just a little misleading at a glance. A better / clearer way to put it would be:
"if you have an unwanted tower of guns mutator, i'm offering a new and loving home for it"
Hope that helps and good luck! :)
Edit: by putting "I'm offering" at the start of your initial post, it just sounds like you are offering the game - whereas mentioning the unwanted game first and then OFFERING to give it a home does not - does that make sense or am I rambling?!?