Coma State Eden is an unforgiving, but tighly designed, arcade-style shoot-em-up. I love this game, it has amazing visual and sound aesthetics, a strong theme, and the main character oozes with personality.
Although it may initially be intimidating, that is because the game starts you out with multiple tools and a strong challenge, which end up being great for multiple playthroughs (since there are 4 difficulties), because you don't have to snooze through easy sections every time .
If you take the time to learn this game's mechanics it becomes a super rewarding and memorable experience, I recommend this game to everyone who loves not only challenging games but also games as an experience, because this one really does stick in your mind.