Gears 4 now offers a ten-hour trial, with players able to access the full versus modes as well as horde mode, while also letting you playthrough act 1 of the pretty decent campaign too. Of course, only play the campaign if you are definitely going to purchase the game once your trial is over. I'm not saying that as you will get annoyed at yourself due to earning achievements for it, but also because the campaign takes a bit to get going, which you would know if you saw my review ;)
If you've not got time to play this between now and June 15th then no big deal. Simply download the free trial while this offer is running and the ten hours will be there for you when you decide to load the game up, even after June 15th. Download the try it free option on this link to get in on this action.