Dark Forest is a decentralized MMO strategy game, built on Ethereum and the Gnosis Chain (formerly called xDAI) with zero-knowledge cryptography. Players explore a massive and procedurally-generated universe, conquering planets and growing a cosmic empire.
With Ethereum gaming, the closed source server model has been replaced by a few open-source Ethereum contracts. This means you can hack literally every other part of the experience to your liking. Dark forest publishes npm packages for its contract addresses, types, and utilities functions and releases an official subgraph to ease the development workflow for anyone interested in contributing.
Beyond this underlying philosophy of strongly encouraging contributions by its community, Dark Forest generally utilizes other fundamental blockchain characteristics such as mining to design creative gameplay elements so that players for example must compute hashes in order to uncover points of interest in the universe, such as the locations of planets and other players. Because of this and its rather minimalistic presentation, Dark Forest is worth looking into mostly for those interested in how blockchain integration can benefit gameplay and that way lead to more innovative experiences.
Nevertheless, the game also features some Play-to-Earn elements, mostly by performing in-game activities that help other players progress and in some cases by being rewarded with cryptocurrency or NFTs for ranking among the top players in specific events. This is more of a reward for active players than a highly profitable Play-to-Earn opportunity though, meaning those who are not interested in its more original approaches regarding gameplay design will most likely find more worthwhile projects to earn crypto.