Steam has started testing Painkiller without bots in single-player mode.

Steam Begins Testing Painkiller Without Bots in Single-Player Mode

The new Painkiller from Anshar, Saber, and 3D Realms was poorly received by fans of the original, partly due to forced co-op. Three months later, the developers have finally decided to add a purely single-player campaign, without live teammates or bots.

An open technical test has begun on Steam for all owners of the game (they will find "Painkiller - Technical Test" in their library): this version includes a "Disable Bots" option. The team is interested in feedback, primarily regarding difficulty levels, in-game economy, interface, and performance.