Like all good games should (perhaps barring things like Dark Souls where you might argue a certain difficulty is core to the experience) Invisible, Inc. offers you several difficulty settings and the ability to customize details yourself. The list of options available is excellent - everything from number of guards and credit modifier when looting, to details like being able to have guards knocked out permanently or disabling the automatic advancement of the alarm system. I think it shows a real faith in their game for the designers to give the player choices like this, which could radically change the player experience.
I apply the same kind of philosophy to games like X-Com, where I'll try not to quit and reload the moment I face a slight setback, but I will maintain a save before every battle in case my whole team gets wiped. Basically, it comes down to how I perceive acceptable losses, and often the manner in which losses occur makes a big difference here. If I think I lost troops to ridiculously lucky alien shooting or a cheap enemy ability, then I'm gonna reload, while losing several veterans in a desperate race to the dropship at the otherwise successful conclusion to a nightmare mission (involving hordes of chryssalids, naturally) is a bitter pill that I can swallow. I can handle looking back on a character and remembering how they died trying to cover the retreat of their teammates, but thinking about my sniper who got shot across the map while behind cover by some sectoid with a pistol and a couple of critical hits just makes me angry (that scenario might be slightly exaggerated, but it's what it felt like!).
All that said, I really think it can work in shorter games. Nobody is going to complain about multiplayer RTS games not having any time rewind or save features, since it'll probably be over in 30 minutes to two hours at the outside. Invisible, Inc. is built around a time limit to achieve your objectives (every mission takes time to reach, and you start with only 72 hours), so if you take a beating in ironman mode, you'll simultaneously not have lost too much progress, and will also know exactly how much time remains before the final showdown, allowing you to easily decide if it's really worth pushing on and hoping you can turn things around with some bold play. Once I finish my Beginner campaign, I have to decide between Experienced and Expert for my second - I think I might well go for Experienced difficulty, then customize it to reduce rewinds to one. I'd like to do an AAR of that, but I still want to do at least one with Cities: Skylines too. So many games, so little time...