Roguelike/permadeath features aren't generally my thing, but Heat Signature manages to soften the blow in at least two significant ways: success, ultimately, loses you just as much as failure; and failure doesn't stop you, it just makes you rethink your next mission's strategy. I'd say "it slows you down," but given you have faster liberation rates on newer characters, depending on how deep into a character's run you were when you died, it might not really even do that.

Probably the most fun I've had with a top-down style game in quite a while. It's not perfect (though its recent update addressed some of the more popular issues, like densely-populated missions with all the guards protected by shields), but most of its flaws work through the game's various challenge systems to make things more interesting, rather than frustrating. I feel pretty good recommending it to anyone who likes top-down action games.