As most reviews have stated, it's FTL with a 40k skin. There are some noteworthy differences, but at its core, from the outer UI to gameplay and progression, it's effectively FTL.

But, it does distinguish itself with some notable variations on existing systems.
Instead of crew levels, you get to fully customize your crew's gear. These can be bought, found in random encounters, or otherwise produced along your journey. Boarding is far more common, and new strategies must be crafted with the understanding that most large ships will send a shuttle to attack you directly.

Some units are able to use psychic powers to summon thralls, teleport enemy and friendly crew alike, and perform utility work. Think of the rare crew abilities of Crystal Crew in FTL; this is heavily expanded upon and remixed throughout.
Shrines/Nexuses of Influence exist in many sectors, and allow you to steer the encounters and events you see during your playthrough. Pledge to a raider clan, and see more raider-aligned events; Pledge yourself to the Empire, and you will see more of their related events appear.

Ships are not purely unlocked by achievement, but are further purchased via score points earned through runs after unlocks. This makes the acquisition of a ship feel a bit less rewarding than FTL, but provides an element of choice.

Graphically, this game unfortunately does a bit poorer than the game it remixes; In some cases, this is perfectly fine - I don't mind a slightly less clean design structure for ships, or less shaded/polished imagery, it's grimy and grimdark - but in other cases, Void War steps past quality-of-life animations and imagery that FTL utilized to bring system power/damage to life on your screen. Shields do not grow thicker or more visually robust as they charge; weapons do not visibly heat or charge up to indicate they will soon fire. In exchange, other graphics are added to make ships feel more impacted by the stresses of battle: Sparks, slight debris, and other visual flair accompanies the lowering of enemy HP. And unlike FTL, a destroyed ship will disgorge the bodies of its crew into space, giving more weight to the action of destroying it.

Story-wise, this game is unfortunately not that well established; the stakes are nebulous. Yes, the Empire is in tatters, and yes, you are going on a FTL-style roguelike adventure to the Empire's coreworlds. But that's as far as the justification really goes. You fight a boss at the end to complete a goal, enter the halls of death or something - it's a cool process gameplay-wise, but the stakes just aren't as well imagined as the original game. There isn't a critical mission with a time limit, with reminders throughout of the weight you carry in the universe; There isn't a foe that you're slowly fighting through and weakening with an end goal. You don't get a chance to immerse yourself in the effect your actions must have on the galaxy. Instead, you adventure, have deadly grimdark fun with some moral and factional decisions that are individually engaging, and suddenly you're at the last sector out of a finite number of sectors, fighting a boss that hasn't been properly foreshadowed or established across your run, whose death conveys no meaning beyond the completion of the game and more chances to explore.

All in all, I would recommend. It's FTL, but it's 40k.

As most reviews have stated, it's FTL with a 40k skin. There are some noteworthy differences, but at its core, from the outer UI to gameplay and progression, it's effectively FTL. But, it does distinguish itself with some notable variations on existing systems. Instead of crew levels, you get to fully customize your crew's gear. These can be bought, found in random encounters, or otherwise produced along your journey. Boarding is far more common, and new strategies must be crafted with the understanding that most large ships will send a shuttle to attack you directly. Some units are able to use psychic powers to summon thralls, teleport enemy and friendly crew alike, and perform utility work. Think of the rare crew abilities of Crystal Crew in FTL; this is heavily expanded upon and remixed throughout. Shrines/Nexuses of Influence exist in many sectors, and allow you to steer the encounters and events you see during your playthrough. Pledge to a raider clan, and see more raider-aligned events; Pledge yourself to the Empire, and you will see more of their related events appear. Ships are not purely unlocked by achievement, but are further purchased via score points earned through runs after unlocks. This makes the acquisition of a ship feel a bit less rewarding than FTL, but provides an element of choice. Graphically, this game unfortunately does a bit poorer than the game it remixes; In some cases, this is perfectly fine - I don't mind a slightly less clean design structure for ships, or less shaded/polished imagery, it's grimy and grimdark - but in other cases, Void War steps past quality-of-life animations and imagery that FTL utilized to bring system power/damage to life on your screen. Shields do not grow thicker or more visually robust as they charge; weapons do not visibly heat or charge up to indicate they will soon fire. In exchange, other graphics are added to make ships feel more impacted by the stresses of battle: Sparks, slight debris, and other visual flair accompanies the lowering of enemy HP. And unlike FTL, a destroyed ship will disgorge the bodies of its crew into space, giving more weight to the action of destroying it. Story-wise, this game is unfortunately not that well established; the stakes are nebulous. Yes, the Empire is in tatters, and yes, you are going on a FTL-style roguelike adventure to the Empire's coreworlds. But that's as far as the justification really goes. You fight a boss at the end to complete a goal, enter the halls of death or something - it's a cool process gameplay-wise, but the stakes just aren't as well imagined as the original game. There isn't a critical mission with a time limit, with reminders throughout of the weight you carry in the universe; There isn't a foe that you're slowly fighting through and weakening with an end goal. You don't get a chance to immerse yourself in the effect your actions must have on the galaxy. Instead, you adventure, have deadly grimdark fun with some moral and factional decisions that are individually engaging, and suddenly you're at the last sector out of a finite number of sectors, fighting a boss that hasn't been properly foreshadowed or established across your run, whose death conveys no meaning beyond the completion of the game and more chances to explore. All in all, I would recommend. It's FTL, but it's 40k.