If Minecraft is getting too easy for you I suggest playing the RPG Immersion Pack from FTB. It's the most relentless and cruel version of the game I've ever played. Every non-vanilla mob kills you in 1-2 melee hits and vanilla armor is practically useless, full Iron only providing 3 Armor Units worth of protection. Jungles are filled with reptiles I can't spell the name of sporting 100 health and rapid-firing archer golems that spawn at night. Snowy forests contain floating snowflake beings that act like Blazes. Deserts spawn Crawlers that will climb through your open window and murder you while you're crafting (true story). Everything wants you dead and it will likely succeed unless you're properly equipped to deal with it. This stuff makes me more angry than Super Hostile, and I've easily died more times in the last few days than during the entire time I've played Minecraft. I even deleted my world while blind with rage from falling into a lava pit while running for my life from some purple creature I found deep in a cave, but I think I'm going to go back for more.