Minecraft
The most generous online game ever made, and one of the few where buying it is the last transaction.
Ten dollars, fifteen years of free updates, and more content than games costing seven times as much.
Terraria is often described as 2D Minecraft, which undersells it badly. Where Minecraft is about building and open-ended creation, Terraria is a progression game — a sequence of bosses, each gating the next tier of materials, each requiring preparation of arenas, potions, and equipment. It has more in common with an action RPG than a sandbox, and its combat is far deeper.
The content volume is the headline. Thousands of items. Dozens of bosses across two full difficulty eras, since defeating the Wall of Flesh transforms the entire world into hardmode and reworks the enemy tables. Fishing, building, NPC housing with happiness mechanics, events, invasions. For ten dollars this is arguably the best value in the medium.
Multiplayer for up to eight is simple to set up and transforms the experience. Boss fights become co-ordinated encounters where one player builds the arena, another brews potions and everyone contributes to the gear check. A shared world across a few weeks with two or three friends is one of the great co-op experiences available.
The weaknesses are presentational and pedagogical. The interface is cluttered, the sprite work has aged, and the game is close to unplayable without the wiki open because it explains almost nothing about crafting chains or boss summoning. Accept the wiki as part of the game — everybody does — and there is very little to criticise.
The most generous online game ever made, and one of the few where buying it is the last transaction.
Extraordinary craft at a low price, still in early access after five years and still worth every penny.
A far better game than the memes suggested, with an uncertain future decided partly by lawyers.