Só Mais Um is a free online platform for Brazilian retro video game collectors, bringing together a searchable catalog, digital collection tools, and ways to connect with other enthusiasts. Its catalog lists more than 271,000 games, consoles, and accessories across 139 platforms, with details such as cover art, editions, regions, and release years. Members can build a digital shelf of physical items, track condition and collection progress, create wish lists, and import existing spreadsheets.

The platform also supports trading, a marketplace, and live auctions among collectors. Sellers can verify possession of an item using their camera; a confirmation badge can then appear on the listing. Só Mais Um notes that this verification does not guarantee a transaction or handle payments.

Additional features include public price reference data, collectible digital sticker albums, communities, achievements, collection labels, and barcode scanning. Visitors can browse the catalog without an account, and the site offers nine built-in mini-games that run on the user’s device