Fallout Shelter is a spinoff title in the Fallout series. It revolves around the vault rather than the state of the world after the apocalypse like the major titles in the series portray. Bethesda studios, in association with Behaviour Interactive, developed the game. It is available on all major platforms, including consoles and smartphones.
The game was praised because of its core gameplay and its graphics. The players build and manage their vaults as the Overseer while the people residing in these vaults are called Dwellers. The players can assign different roles to the dwellers and are responsible for their well being.
The main criticism that the game faces is the lack of a definite ending, unnecessary microtransactions, and a lack of depth. Fallout Shelter Online is the spiritual successor of Fallout Shelter that aims to rectify these mistakes. Gaea Mobile is developing it rather than Bethesda. The game is already released in China and some parts of Asia on Android and IOS devices.
The main attractions of the game (as the name suggests) are its online mechanics i.e., the PvP battle system. It also features the PvE combat system, a guild system, and different legendary heroes featured in the Fallout titles (in the form of collectible cards). The core gameplay, however, stays the same. The players serve as the Overseer of the vault they build, upgrade and defend. The players can also challenge anyone online. It will be interesting to see when players from other regions will get the game and whether it will be available on consoles.
To see whether the game is available in your country head over to the official site here.