How can Blockchained Games be free ?

Hi, i was recently looking at website that lists every games that are currently based on the Blockchain,

And as i understand it, they're like a hybrid type of games meaning that they have the major part of the datas stored in servers and some tokens and assets on Blockchain

I get that this is necessary for the gas price because it would be terrible to have the whole program running on the Blockchain,

So why games like Lost Relics are free but still use Blockchain to make tokens and assets, shouldn't players be paying for gas fees ?