Project Abyss [official site] has exited Steam Early Access and properly launched into the depths. Tall Story Studios' 2D underwater RPG puts you in control of a mini-sub as a diver looking for riches in underwater salvage. You'll quickly be caught up in a story that puts you in the line of fire as you attempt to unravel a world-shaking mystery.
You can play in and out of your submarine, and that's good because I'm claustrophobic. When you reach a tight space, you'll have to exit the safety of your sub and deal with nothing between you and the crushing ocean except a wet suit. There're a ton of exciting set pieces in Project Abyss, and as you progress through the game, you'll explore a sunken airship, pirate ships, and World War-era submarines.
Project Abyss has pixel-style graphics, but the simplicity of the visuals belies a relatively deep game. There are a full day and night cycle, and upgrades to your sub along 3 tech-trees. The physics also give a unique feel to the game, as you'll have to compensate for ocean currents, and drill your way through rock as you explore the ocean's depths.
You can get Project Abyss now on Steam for £5.99/8,99€/$8.99.