The game has faucets in it for both testnet ETH and testnet SWAY, make sure your wallet is on the Sepolia testnet network when you enter the pre-release.

The faucets are in the upper corner on the right menu, you go to store and you should see something like this:

If you run out of testnet ETH, there are other non game faucets in starknet like:

https://starknet-faucet.vercel.app/

https://blastapi.io/faucets/starknet-sepolia-eth

The game is still buggy, it's in pre-release after all, and sometimes the faucets are down.

Took me like a day to understand the basics of the basics, and I'm still trying to figure things out myself, which is fun 😅 reminds me of the times where you had to figure things out in games without youtube tutorials