This review applies to Terraria 1.3.0.8 and earlier.

The essence of Terraria is that it prioritizes fun! It's not a game where players must fear losing progress due to forgetting safety measures or manage breakable tools. The game knows how to bring out a sense of enjoyment and achievement. Grinding is an option, not a requirement or an excuse to drag out game time. Besides, there is much to discover and do in the game. Clocking in at 1,000+ hours, having all 88 achievements, and introducing multiple friends to the game should be indicative of that. With that being said, I'll list some pros/cons I've found memorable.

Pros

• Customization: There is a staggering amount of customization available in-game. You not only can choose from several basic character designs but also have a plethora of armors, costumes, accessories, and pets for your character. You can also color/dye any of your equipment and get all sorts of flashy effects. Dyes aren't consumable, so you have few restrictions on perfecting your assemblage.
  
• Exploration: The Terraria world may be finite, but it is incredibly diverse. Each biome has its own personality and houses many unique elements. It takes a minimum of three worlds to discover everything, and that's only with absurd luck (see "The Creation of the Guide" painting). The game additionally has an impressive number of flavor. That rubble on the ground can be dug up, and a Worm might pop out from it. You can reignite the burnt-out Campfire in that small cavern. You didn't think that NPCs could fend for themselves during a Blood Moon or invasion, did you? Just when you think you've learned everything about the Terraria world, you discover something surprising.
  
• Creativity: Terraria is as much as about creating your world as it is exploring it. Blocks and furniture are not just for aesthetics, but they also introduce some neat mechanics. Players looking to engineer stuff will enjoy the contraptions possible by the wiring mechanic, and designers will love being able to paint the overworld with a wide spectrum of colors. Terraria features innovative design at its finest.
  
• Progression options: Like any good RPG, there's a great sense of progress made in a playthrough. You mine or slay enemies for the materials needed to upgrade equipment, and the world is bountiful enough that this progress never feels linear or constrained. Even the achievements flow nicely, never feeling too easy, cheap, or absurdly difficult.
  You never need to rely crutch items to make progress. Rather, in my experience, my friends and I frequently had too many options and had to reluctantly store away some of our neat loot. There is always something to switch to if a playstyle becomes easy or repetitive.
  
• Balance: A game can become boring if there is a certain playstyle players fall into. Terraria manages to find the right balance so that all playstyles have a fair shot at completing the game. There is no bottleneck or singular Infinity+1 Sword needed for progress.
  
• Diversity: Terraria promotes itself as a game for any type of player, and that claim certainly has truth in it. The game has gameplay suited for battlers, explorers, and builders, and I can also tack on several options that appeal to other types of players. Collectors will balk at the quantity of items and achievements offered, and players can challenge themselves to make progress with nearly any conduct. Play with only melee/ranged/magic/summoning weapons? Sure. A yo-yo only run? That's popular! No crafting/mining? Certainly. Play the entire game upside-down? Of course--and that's bug-free! If that's not enough, you can fire up a world in Expert Mode for the extra challenge. There's something for everyone.
  I've had a friend who would ask on his first playthrough 'Can I do ____ in the game?' and I could answer in the positive the majority of the time. Just for starters, you can teleport, build trap-filled dungeons, set up PVP minigames, and record the soundtrack. The game's breadth is incredible.
  
• Automation: Terraria would be daunting without any form of automation. You have thousands of items, hundreds of monsters, dozens of mechanics, and an expansive world to build on or dig through. The game offers much to ease the burden of management. Auto-select picks the right tool rather than requiring manual selection. The smart cursor allows for one-click digging. Quick-stacking is much more convenient than depositing items one-by-one, chest-by-chest. Farming is not only feasible but easy. Making measured builds is simplified with items like the Ruler. The game naturally provides the player ease-of-use tools so a playthrough can be focused on the fun stuff rather than on chores.
  
• Performance: Many games fall off a prospective player's wishlist due to system requirements. Terraria is a game that features a crazy amount of sprites, particle effects, physics, lighting, and entity interaction. Being a 2-D game only nets you that much speed before optimizations come into play *cough*Starbound*cough*. The game's requirements are reasonable and the gameplay is optimized such that it doesn't require a bulky system to run on. I was able to run it decently on a 2007 year-old desktop on Windows XP with low-end specifications. The performance of the game to medium- and some low-end systems makes it accessible to a broad demographic of players. On the other hand, if you have a high-end system, go ahead and fire up that Color lighting mode and enjoy Terraria in its full glory.
  
• Quality of life: Many games have little quirks that people have to accept to enjoy. Not only is Terraria's gameplay mainly devoid of bugs, but it also buffs out these quirks. Players are separated from worlds, allowing for easy singleplayer-to-multiplayer transfer. Characters can ascend blocks without needing to jump. Chests containing items don't explode if you try to harvest them. Keys are easily remappable for those familiar with alternate control schemes. Quick-stacking skips 'favorite' items. You can use the in-game system for taking wide screenshots for giant builds. You can set player configurations to ease the smallest of annoyances. In general, you never feel you're fighting the game's controls and interface.
  
• Continued updates: It would be very easy for Terraria, as popular as it is, to offer game expansions as paid DLC. The developers, instead, make their continued updates absolutely free to owners of the game. The developer-community relationship is superb.

Cons

• New player friendliness: The in-game help system is stunted, and players can easily become overwhelmed by the ever-growing number of toys in Terraria's sandbox. Many people resort to a guide to help them through the game.
  
• Grinding: While the game does not require noticeable grinding to progress, several tangents in the game require patience and luck. That fancy teleportation item pretty much necessitates a farm in the Hallow. The last component of a PDA could be hundreds of monster drops or fishing quests away. At a rate of one quest per in-game day, the 200 fishing quests achievement would require 4,800 minutes (3 1/3 days) to complete without resorting to tricks. It can be frustrating to have an achievement be left incomplete as a stretch, yet Terraria is not above this issue.
  
• Moddability: Terraria is extensive enough that it doesn't need additional features, but people have been able to decode the game and develop external software and mods for a better game experience. It would be a boon if the game was open to the modding community for extended gameplay.