 If you liked
Shinseiki Evangelion
|
 ...then you might like
All You Need Is Kill
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In both stories, humanity is on the verge of being extinct by frightening yet spectacularly designed alien creatures, who seem to be way too powerful to defeat. Nonetheless the protagonists are literally forced to keep trying, (using futuristic high-tech gear or mecha-like suits/machinery, if you will) and experience a lot of physical and emotional pain in order to do so. Both are very sci-fi and come with nice twists.