If you own the PS3/Vita version download the newly released PS4 version free.
Glad I must have "purchased" this from PS+.
Single-handedly turn back the evil invading Titan army! Drive back the aliens across the Solar System, and finally defeat them on their homeworld in this modern remix of classic arcade shoot'em'ups. Purchasing this content entitles you to the PS3™, PS4™, and PS Vita versions!