It's a pretty typical sample of my playing experience. Creep. Die. Repeat. I wound up beating the level after another 2 and a half hours. There was nothing particularly special about my last run. In the end, it was a matter of luck - the enemies spawned in a pattern that allowed me to see enough of them early enough that I only died three times rather than four.
I'm finding that the biggest part of playing Takedown: Red Sabre is managing my emotions. I have to be aware of and sensitive to the game's tension (because, while being careful won't keep you alive, being careless will kill you), but not get so into it that the frustration is overwhelming. And amidst all this, I also have to carefully manage my attention so that the tedium of repetition does not wear me down and cause me to quit.
You never quite realize how long five hours is until you have to relive the same three minutes a hundred times in a row.
Only a hundred more deaths to go. I'd lay the odds of me beating the third mission at around 50/50. Mission 4 is never going to happen.