As announced last month, Transformed is one of five games that Plus members will be receiving for free in December. The others are Borderlands 2, Dyad, and GRID 2 for PlayStation 3, and Urban Trial Freestyle for Vita.
Also of note for Plus members this week is the fact that this is the last chance to get Soul Sacrifice for free, as it will be going back to its regular price on December 31. Additionally, the Killzone: Shadow Fall multiplayer trial -- players will be able to try the PS4 game's multiplayer component from December 28-31 -- will be playable beginning later this week. The game itself can be downloaded now in order to avoid waiting once it can actually be played.