It took me a while to get back into it, but I'm glad I did. I really liked the plot twist in the middle of Hephaestus. It almost averts the idea of having objectives in a shooter. Why are you doing these things? Well, the game told you to. Okay then!
The difficulty spikes are so strange, but even when the game kills you, there are absolutely no consequences; you just revive at a vita-chamber. In a way, this keeps you playing because you WILL be able to finish the game, simply through pure perseverance, but it does cripple the immersion factor and tension of being low on life. Others have criticized the game for this design choice, but since there's an option to turn it off, you can't really fault them. Personally I prefer to have the option than to simply have it nonexistent by design; it allows more players to play through the game, even if they're not good at shooters, or just not good at console controls.
Seriously, fuck console controls in shooters.