One block broken, another placed, and the horizon becomes a project: Minecraft sets no goal, it lets them grow from the player's own hand. Mining leads to smelting, smelting to building, building to exploring farther for better materials, in a spiral where each rung opens ten more. Night, the mobs, the next cave always give a reason to stay a little longer. Caution: with no imposed aim, ambitious builds can stretch sessions toward no clear end.
A sandbox with no edge and no real ending: you dig, you build, you explore infinitely generated caves, you face the Ender Dragon and then start over somewhere else. Survival and creative modes, redstone, automated farms and multiplayer turn every session into a personal project. That raw freedom, where each player invents their own goals, guarantees a potentially limitless lifespan.