Mercury is a Tier 4 ship in Starblast.io. It one of two Pulse-Type Tier-4 ships, the other being the Vanguard. The Mercury fires a frontal pulse and two slightly converging small lasers from the sides. It is a relatively large ship with average mass, that moves at a good speed but has good acceleration for its maxed speed. It is incredibly efficient with energy, and can fire many times before running out. With energy upgrades, it almost never runs out. (before damage is upgraded)
When playing the Mercury, it is best to upgrade Damage (Do not upgrade Damage if you are a miner) and Ship Speed first, due to its nearly inexhaustible energy reserves. The side-lasers prove virtually useless, and the main shot must be aimed well. Un-upgraded, the Mercury is weaker than other ships of its tier. A fully-upgraded Mercury is still not a match against most ships, however, is able to beat the Side-Interceptor, and potentially the Crusader in a duel, in its tier.
The Mercury has a Tier-6 version of it, the H-Mercury, that shares its appearance but few other characteristics.