I'm rating the current state of the game, which I think has drifted a long way from what made it work.
The original design had almost nothing in it and that was the point — a handful of blocks and a day-night cycle, and everything interesting came from the player. What's been added since is mostly content rather than systems: more mobs, more biomes, more decorative blocks, more structures with loot in them. Each addition is fine. Cumulatively they've turned a sandbox into a game with things to go and do, and the things to go and do are not very good.
The mob votes crystallised it for me. A community voting on which single feature gets made, annually, for a product owned by Microsoft, is a content strategy, not a development one.
Performance on the Java version is also genuinely poor for what's on screen, and has been for a decade.
A C for the current version. The 2011 version is an S and I'm aware that's an awkward position to hold.

Minecraft
2009 · Action, Simulation, Arcade