It only gets stars for game play.
SPOILERS BELOW for why the game overall gets a bad review.
The story has no ending where the main character survives. The whole game strings you along with a list of tasks to perform to save you from the broken implant. Then at the end (for all endings) you are given a choice of only having a few months to live as yourself or to surrender your body to the Johnny personality. At the end of the game you are literally in the same condition as the beginning (or worse) , just higher level with more stuff.
So while the game play is fun (if you can push through all of the crashes- ever hard of software testing?), If you don't want to feel like you wasted your time for no accomplishment, you may want to avoid this purchase.