Wow, this has improved a ton since I last tried it. I think when I used it years ago it didn't have many mods but now I can make it better than minecraft. It also runs a ton better on my Linux machine and on my iMac. You can make it really close to Minecraft if you want with a few mods but I like how it feels as is.
Out of all the minecraft clones, this is the best one i've seen. If you can't afford minecraft, this is a great alternative. I really wish it had graphics option though. I'm running off a GT520, so the game doesn't run crazy well.
You can install your own selection of mods from an in-game catalogue or look them up and download them manually. You can install mineclone2, which brings it very close to a minecraft experience. Don't install the game from here unless you made sure it's the latest version. You can find the latest version on minetest.net/downloads
ahhh.. great but can you add invert y-axis because i'm not accustomed with the default. and add mouse sensitivity. please
Don't waste your time on Minecraft. Get this instead - Minecraft isn't much better, but with the Mods you can make Minetest FAR better than Minecraft. Be prepared to wrestle your children away from the Computer.