So wow, this was a real kick in the teeth. Super Metroid was definitely challenging but this game really takes the cake with it. I've read that the first playthrough here is one of the toughest experiences in the series and, though having only played this and Super Metroid, I can fully believe it. Pretty much all enemies hit for a fair whack of a damage, bosses are a real pain the first few runs through before you get used to them, this game really just kicked my ass and a few times it wasn't in a "rewarding to beat" way but a "holy shit fuck this" way, if you'll pardon the language. There were absolutely moments of greatness that I'd expected coming off the back of Super though, the atmosphere while not quite as peak as its predecessor is definitely strong. Whenever SA-X shows up its almost survival horror like as you are completely useless to face it and have simply to run and hide and hope for the best. A couple of the bosses were intriguing and rewarding in presentation and defeat respectively, namely Nightmare and the second fight with the security robot. However, a couple more of the bosses were absolutely painful to fight including but not limited to that bastard spider and the plant thing's entire room being like a single room bullet hell. I'm still glad I played this game, it bringing out my violent tendencies a few times aside. Fusion is a worthy sequel to Super, continuing the story in an interesting way, and definitely keeping up (though never quite matching) the fantastic atmosphere and exploration that you'd come to this series for. Not sure if I could play it again though, I value my heart-rate a little too much.