It’s been a slow couple of months for Arc Raiders . New content has slowed to a trickle while player complaints keep piling up. That should all hopefully change with Riven Tides, the extraction shooter’s biggest update ever. It goes live on April 28. Here’s what it includes. The main additions  are a new map and a hulking new Arc Turbine enemy that floats in the sky. The map is set along a coastline and includes a resort and a dockyard to scavenge through. Tennis courts and lavish ballrooms lie abandoned and dilapidated as seagulls circle overhead. The collision of breezy vacationing and grim apocalypse offers some great initial vibes in the trailer: What else is new in Riven Tides?…