Square Enix took a shot at the mystery game bundle thing last year with the Holiday Surprise Box, a package of five games, valued collectively at more than $80, for a tenner. The bundle ended up containing Lara Croft and the Temple of Osiris, Thief (the new one), Final Fantasy XIII, Life is Strange ep. 1, Final Fantasy XIV: A Realm Reborn, and a few coupons for the Square Enix Store. And it must have been a reasonably decent success, because it's happening again.
The Square Enix Easter Surprise Box is basically the same deal as the Holiday Box: Ten bucks gets you five games, names to be revealed later, with a collective retail value in excess of $80. The games will be delivered individually through Steam, and they'll be giftable, so you'll be hand them out to family, friends, and/or enemies as the situation warrants, if you decide you don't want them for yourself.
The Easter Surprise Box is available for purchase now, and will remain so until March 20; the contents of the bundle will be revealed on March 21. Be aware, as Square Enix warns on the purchase page, that as a surprise box, “all purchases are final and non refundable.”