PC version

The Sims 2: Pets allows sims to own cats, dogs, birds, and a fictional guinea pig-like species known as womrats.^{[15][note 1]} Pets can be acquired during gameplay or made using the "Create a Dog"/"Create a Cat" tools,^[17] which allows players to design a breed from scratch, including features and coat colour. Players are not limited to naturally occurring colours.^[18][19] Pets work similar to other sims; they have needs or motives that need to be provided for, such as Hunger, Energy, and Hygiene. Unlike other sims, they cannot be directly controlled by the player and instead act autonomously.^[20] Pets are able to have careers, and can in theory be a family's primary breadwinner.^[21]

Following the introduction of supernatural or "occult" sims in prior expansion packs,^[22] Pets adds the ability for sims to become werewolves.^[23] Werewolves are normal sims during the daytime, but at 8 p.m. in-game time turn into anthropomorphic wolves. They have the ability to summon wolves, and train pets at an accelerated rate compared to normal sims. Over time, a werewolf's personality evolves to be more outgoing, less nice, less neat, more active, and more playful, and they automatically gain points in the Body skill. Servos from The Sims 2: Open for Business can be turned into werewolves, and sims can be both werewolves and vampires or zombies.^[24]

Unlike prior expansions, Pets has little content relevant to overall gameplay.^[19] It nonetheless expands the game's building options, including making it possible to build diagonal walls and rooms^[25] and octagon-shaped rooms.^[26] It also adds new cheat codes, allowing players to control pets, modify roof slopes when building, and freeze pet aging.^[27]

Console and PSP versions

Unlike the PC version, the console version of The Sims 2: Pets is a stand-alone game. Senior producer Rod Humble described it as a "more advanced version" of the original version of The Sims 2 for consoles, which had been released the year before. The game was released for PlayStation 2, GameCube, PlayStation Portable and Wii; no Xbox 360 version was released, due to the high competition expected on the platform during that release window.^[13]

Like the base game across platforms, the console version of Pets is an open-ended sandbox game. Goals the game encourages, but does not mandate, include upgrading the town square of the in-game neighbourhood; unlocking pet colours, markings, and collars to use in the Create a Cat and Create a Dog processes; and unlocking new sims to interact with.^[28] Fundamental mechanics are similar to the PC game, but work in different ways. For instance, the aspiration (long-term driving goal) and want (short-term desires) systems are retained, but the selection of aspirations is different, and the player can change a sim's wants on demand using a "Call Therapist" function.^[29]

The console version of Pets has a single neighbourhood with a downtown or "town square" area, which exclusively contains pet-related businesses. Rather than simoleons (the usual in-game currency across the series), the town square deals in "Pet Points", which are acquired through fulfilling a pet's wants.^[30][31] As the player earns and spends such points, the town square is upgraded, expanding the businesses located there and the range of objects available in them. Pet Points also allow the player to acquire codes that unlock secret items.^[32] There are no non-pet-related businesses or recreational options.^[33]

Game Boy Advance and Nintendo DS versions

The versions of Pets for the Game Boy Advance and Nintendo DS are more structured than on other platforms. The DS version is premised on playing as a veterinarian running an animal hospital, while the GBA version incorporates role-playing game elements.^[13]

The DS version of Pets, on account of its premise, has a more direct focus on animal care than other entries. While caring for a sim and their own pet, the player treats a steady flow of cats and dogs with any one of five diseases.^[34] The interactions available are limited compared to the PC game.^[34][35][36] The game includes both cats and dogs, but their behaviour and interaction work the same; Craig Harris, reviewing for IGN, complained that cats "roll over and beg, and fetch a ball with the same animation sequences as the dogs". Pet training is also possible, using a rhythm game-like mechanic where the player completes patterns on-screen to train a trick.^[35] The GBA version is loosely structured around training a pet and competing against non-player characters. As Sims earn money, they can buy "trick scrolls" that allow teaching a pet a new trick. The game as a whole is based primarily around formal minigames, including pet walking, training, and competitions.^[37]

PC version

The Sims 2: Pets for PC received an aggregate Metascore of 76, indicating positive-leaning reviews.^[42] Reviewers praised the pets themselves for their realism and design^[41][43] but criticised the expansion pack's overall lack of content and narrow focus on its subject matter.^[21][44] Multiple writers found the expansion's limited scope disappointing compared to the broader additions of previous expansion packs.^[19][45]

The models, animations, and behaviours of the pets were well-received; Computer and Video Games's Stuart Bishop—in a positive review—called their "needless detail" a surprise. Bishop and IGN's J. Habib both favourably compared Pets to The Sims: Unleashed, a similar expansion pack for the first game. Habib noted Pets' expanded customization, including the ability to create new breeds. Bishop called attention to the game's fluid and naturalistic animations compared to Unleashed, stating that cats and dogs in Pets moved realistically rather than, as he chose to put it, "running only at 90-degree angles like some demented autistic creature".^[19][41]

Pets' markedly narrower scope than prior expansion packs was a subject of discussion. Habib described Pets as "hands-down the least significant and useful of the Sims 2 expansion packs".^[19] Charlie Barratt at GamesRadar juxtaposed it with the prior three expansion packs for the game; while University, Nightlife, and Open for Business had made substantial gameplay changes, Pets was more monotonously focused on a single element.^[45] Multiple reviewers felt that the expansion was unlikely to appeal to new players.^[18][43][44]

In 2022, Gabrielle Castania at TheGamer ranked Pets in seventh place out of The Sims 2's eight expansion packs.^[46]

Console and handheld versions

Reviews for the console and handheld versions of Pets were mixed to negative. Metascores for the console games all fall into the "mixed or average" range, ranging from 57 for the PlayStation Portable rendition to 68 on the PlayStation 2. The handheld version of Pets for the Nintendo DS received a Metascore of 49, corresponding to "generally unfavourable" reviews.^[48] Pets was considered an improvement over previous console Sims games; Juan Castro at IGN felt it "improves upon its console predecessors in every way imaginable",^[49] while reviewers with mixed perceptions on the game as a whole nonetheless praised it compared to previous installments.^[47][50] However, reviewers criticised its limitations compared to the PC game.^[47][51][52]

Pets for console was unfavourably compared to dedicated virtual pet games; Liam Kavanagh at Eurogamer recommended Nintendogs as a better option for virtual pet players, while a Computer and Video Games staff writer described it as "a variation on Tamagotchi that's been roughly crowbarred into The Sims 2".^[47][53] The game's limitations compared to its PC version were a recurring subject of discussion. Critics described it as "feel[ing] like an expansion pack"^[50] and referred to its inability to be built upon the same way as the PC game. A writer for Digital Entertainment News criticised the general concept of console Sims ports due to their inability to become "one very-full-featured master-game", giving the example of a hypothetical Nightlife console port that players would be unable to synergize with Pets.^[54]

Reviews for the PSP and GameCube ports drew attention to their limitations. Orry, reviewing for PSP, criticised its frequent loading and lack of multiplayer options.^[50] Gamestyle's Andy Lucas praised the GameCube version compared to contemporary releases such as Need for Speed: Underground 2, alongside EA's commitment to the declining platform; nonetheless, he found the game as a whole "competent but uninspired".^[51] Mike Wilson's N-Europe GameCube review was strongly negative, disparaging the loading times and controls and stating its inferiority to the PC version "could possibly tarnish your view on future Sims games".^[52]

The handheld versions of Pets were poorly-received; GamesRadar stated the DS version "needs to be put down".^[36] Reviewers disliked its "mutant, low-poly" graphics; the apparent shortcuts it took, such as cats behaving identically to dogs;^[35] and its inferiority to Nintendogs, a similar simulation title focused on pet care.^[34] The Game Boy Advance version, while "not quite as dull",^[55] still received criticism for its balance issues, lack of personality, and convoluted plot.^[37][55]