"Fuck it, that works."

These four little words, so frequently uttered while playing Tom Francis's excellent sci-fi action-roguelike Heat Signature, really get to the core of the whole experience. The best laid plans of mice and keyboards, after all, never stand up to scrutiny when you're in the thick of an increasingly FUBAR mission and have to think on your feet, or while flying through space, or while teleporting through solid matter, or any other number of dramatic scenarios.

Heat Signature puts you in the space boots of any number of procedurally-generated mercenaries, operating out a newly reclaimed base sitting between several major hostile factions. By completing missions via terminals, you gain more power over these rivals and can eventually start annexing their bases by inspiring their owners to rebel against the oppressive hegemony with your daring feats. Missions usually boil down to infiltrating a ship via a speedy lander craft, making your way to the mission objective with violence and/or stealth, stealing/rescuing/capturing/assassinating the target, and making a break for it. If the lander's airlock is too far away, a nearby window suffices: you can survive in space long enough to remote control your lander to sweep you up. Maybe you decide you want to enter the enemy ship the same way; I haven't figured out how yet, but then I'm probably too much of a wuss to try.

The ingenuity of Heat Signature - some of which is delivered by the game, some of which the player has to BYOB (Bring Your Own Boldness) themselves - is in how open the game is to improvisation. The core gameplay loop involves exploiting a pause feature to plan your next move - if there's a room full of enemies about to shoot, and it'll take too long to reload your gun to kill them all in time, what else can you do? Swing the wrench you have as a back-up? Throw it instead? Teleport a second gun into your hand rather than wait for the first to reload, and then teleport the next guy's gun after taking him out? You have all the time in the world to consider, as long as there are options available. However, the game's in its element when you have more than a handful of alternatives provided by the gadgets and gizmos you've found: a key-cloner can replicate a guard's high-level key without requiring an encounter; a subverter or crashbeam can take care of a turret or an enemy's shield; a cleverly-placed acid-trap can remove a tough guard's otherwise impenetrable armor; a swapper or sidewinder can teleport you past a clump of guards bottlenecking a vital corridor of the ship; and so on. The longer you play, the more likely you are to find gadgets that recharge every mission - you don't need to be quite as stingy with those - or even recharge mid-assault.

It's with the confidence gained from your experience and new hardware that you start taking on harder and harder missions, knowing your perspicacity is likely to save your bacon even against the harshest of odds. The game duly complies, starting with "hard" missions and working their way up to "audacious," "mistake," (as in, "I've made a huge mistake") and finally "glory." (Glory missions, rather than reward you money, instead rewards you bragging rights on your friends leaderboard.) Each of your randomly generated heroes also has a randomly generated "personal mission"; the completion of which finally allows them to retire, like in a heist movie. Retiring a character, sometimes necessary if they've been blasted out of an airlock one too many times, allows you to bequeath your best item to your successor. Claiming new bases also provides permanent bonuses to your faction rather than your immediate character: these might range from better equipment in stores to stronger starting items and a higher starting cash total. Between these inheritances and base bonuses, the game's "start from scratch" roguelike limitation becomes that much more bearable. If you really get attached to your current character though, you can simply choose to keep them out of harm's way: easier missions, missions where enemies only carry stun weapons, or a special type of lander that can instantly grab your free-floating form, for example.

I thought I'd sworn off Indie roguelikes because of how pointless they feel, guiding an algorithm through a series of other algorithms to accomplish yet another algorithm, but I'm glad to have given Heat Signature a shot. It does feel like an evolution of Tom Francis's previous game, Gunpoint, partly because you're defenestrating yourself at every opportunity that arises but also in the way both games force you to jerry-rig new solutions to immediate and unforeseeable wrinkles, exercising a mental muscle that most games can't or won't reach. I retired my first character, Lacerta Singye, after one too many bumps taking on missions I had no business attempting, but her/his successor Cascara Vega is proving to be an absolute monster: thanks to a perk that provides better items from chests, I've now got several rechargeable gadgets that frequently allow me to earn various mission bonuses like bloodless (no kills), enigma (no witnesses), silent (no alarms), and unscathed (no injury to self). Unfortunately, Cascara's a little too good: they now earn less acclaim per mission because they're famous, so if I want to keep liberating new bases at a clip I'll eventually want to switch to a newbie. Albeit, a newbie with the advantage of Cascara's passed-down self-charging shield, their zero-cooldown "Instant Connection" melee baton, or a long-range crashbeam with near-infinite uses. Sky - and space - is the limit, as long as I remember to never bite off more than I can chew; a rule I break as often as I break a space merc's nose or an unusually fragile transparent aluminum window.

Rating: 5 out of 5.