I got this game a veeeeeery long time ago (it was still in early access if I remember well), and it is still by far my favorite once-in-a-while game. When I'm not sure what to do, I launch Reassembly and play for a perfectly undetermined amount of time.

Reassembly is the perfect relaxation game. The music is both calm and upbeat, making the transitions between travelling, gathering and fighting almost seemless. Vector graphics also help to the surreal feel, and they allow the game to run very smoothly on most computers (as long as you keep away from the damn spiky plants, spamming projectiles until your computer fries). Fighting is also a spam-festival, but somehow keeps your game running good (and there is never FPS drop: only a physical simulation slowdown), and it is just exciting enough to be fun without making you hyper-active like playing Quake on accelerated speed after injection of pure Montain Dew essence. Death happens a lot, but isn't too punishing most of the time, and you usually tell yourself "oh, well" and keep going. Building is complex enough to make you activate a few brain cells without frying them, and permissive enough to allow for some beautifully shaped motherships,or if you are like me, spamming of pulse lasers to make an one-shot cube. Speaking of absurd powerful weapons, The tech system (a.k.a factions, unlocking weapons and upgrading your ship) is diverse and smooth enough to keep you going for quite some time.

My personnal recommandation is to spam the same mid or end-tier weapon to make your gunships, except for the tinkrel (purple guys) able to make their own weapons: here just make a fat-ass death-pouring valve, it's hilarious. And of course never forget the anti-missile cannons.

My personnal favourite faction is the Red, because the lack of shields (hardest faction, by the way) forces you in making a swarm of well-designed ships, usually quite cheap and fast to produce. Unless you try to attack a ridiculous player-made gunship, few fleets can compete with a 100 ships army.

The only complain I have is the lack of true multiplayer: you can see other player-made fleets in your world (agents), but that's it.

Otherwise, I highly recommend getting this game.