It is just like MineCraft. Some changes include it being free to play, not owned by Microsoft, fugly default textures (texture packs available), 3x3 crafting inventory (no crafting table), trees grow fast from saplings, items stack at 99, you can basically pick up anything you destroy such as grass and leaves, loads up pretty fast,
no viruses, has people playing on multiplayer servers, supports modding (Even linking to how to mod it themselves). Pretty much set in that core Minecraft environment. Didn't see any mobs running around in 2 days in-game though it claims they exist.
I guess if you've ever wanted to try MineCraft or something like it, you should try this out. They should really change that name if they plan on going somewhere with it, imo.
You don't need an account to play, just download, unzip and launch minetest.exe in the bin folder.