Is Planet IX Free-to-Play?

Planet IX is not a Free-to-Play strategy game, and one of the popular web3 games. You need NFT to earn in Planet IX. NFT. You need a Land NFT called PIX for staking and earning Waste, which you can sell to get tokens. 

Are there any pre-requisite to playing the game, such as Metamask wallet, etc?

To play Planet IX, you must open your browser and their website. After that, connect your wallets such as Metamask, Crypto.com DeFi Wallet, Bitkeep, 1inch, Brave Wallet, Wombat, Coinbase Wallet, or WalletConnect. You can conveniently access the games directly through your browser and ensure you have Land NFT and $MATIC on the Polygon network to facilitate transactions.

What are the advantages of paying or investing more?

The advantage is you can earn more resources, of course, and also have more assets. Besides that, you can also become the top leaderboard and get more airdrops because the activity points you get are higher.

Can players who pay or invest less be competitive or enjoy the game?

You can enjoy playing Planet IX but cannot be competitive against players who invest more in the games. Because only a little can be done, and they can only claim free Tile Contracts.