Helldivers 2 is technically free via PlayStation's loyalty program, but only if you've already dropped roughly $1,000 on games in the last year and a half

gamesradar.com:

It's fantastic news for any hardcore fans of PlayStation's somewhat forgettable loyalty program, as it's now possible to grab a copy of Helldivers 2 without spending any extra money. Unfortunately though, that's assuming that you've already spent lots of money in the last year and a half, to the point where claiming this reward really doesn't seem realistic for a lot of people.

In case you were unfamiliar, the PlayStation Stars loyalty program launched in October 2022, and allows users to complete 'campaigns' (tasks such as playing specific games) to earn digital collectibles and/or points, which can be redeemed for rewards such as store credit and games. PlayStation Plus subscribers can also earn points whenever they spend money in the PlayStation Store, although the 'exchange rate' is pretty brutal, as you can expect to earn around 10 points for each dollar you spend. Oh, and these points expire around two years after you've earned them, too, so you can't keep saving them up forever. 

Theoretically though, you could have been saving up your points since the program's launch, in which case you might be able to afford Helldivers 2, which is one of the latest rewards available to claim. To be exact, you'll need 10,000 points to redeem it, which, assuming that you've not been completing any campaigns, you'd have to have spent around $1,000 to earn. Even if you've finished a few campaigns here and there, it seems more than likely that you'll have to spend an enormous amount of money to make up the difference.

Bizarrely, saving up all of these points at once doesn't give you any advantage over simply redeeming your points on smaller chunks of store credit, either. For 1,250 points, you can earn $5 of store credit, so you'd still need to spend 10,000 points to rack up enough credit to buy Helldivers 2 manually. If you're signed up to the program, it's always worth considering grabbing this credit for discounts on games, though, as purchases and completed campaigns