Privateer: ASCII Sector is a cool space exploration game with roguelike elements, it features a pretty fun trading and mission based schema with space combat and ship upgrade elements. The game is still being development but it is fun to play already; it is full of small details such as federation ships inspecting you for contraband and space travel via warp zones.
Your starting ship is pretty weak and slow, so you will have to take a lot of care if engaged in combat, with time and some missions acomplished you will be able to buy faster, bigger ships. Space combat is simple yet you have a lot of options like handling your shield levels and selecting from your different weapons.
Exploring the space may get a bit tiring, although there exists an autopilot feature, but most of times you will be wandering around empty star clusters. Autopilot stops too far from navpoints so you still have to travel a bit of empty space.
The game doesn’t feature music or sound effects, which would add a lot to the space exploration phase. I end up playing some techno tracks in the background while playing this.
Browse the official website, including screenshots and a forum. The game already sports a nice degree of complexity, and I am sure the author would appreciate your comments!