You can play them for free, but advertising them as "free to play" is deceptive as that implies that you get equal access to the whole game without expense.

"Can be played for free" is not deceptive but doesn't push the right buttons to manipulate people in to engaging before you hit them up for cash; they can see it coming and so many won't play.

Mandating better information for consumers seems unlikely to be wrong in almost all cases. [A counterexample would be if it's prohibitively expensive for companies generally to give the information].