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 2 small lasers from the sides. It is a relatively large ship with average mass, that moves at a good speed but has very low acceleration. It is incredibly efficient with energy, and can fire many times before running out. With energy upgrades, it almost never runs out.
When playing the Mercury, it is best to upgrade Damage 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. Unupgraded, the Mercury is much 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.