It turns out that this game's single-player component requires a decent level of graphics performance. Even at the basement Low quality preset and a 1280x1024 resolution, we found that certain entry-level discrete cards are simply not fast enough for playable performance.
The Radeon HD 6450 and GeForce 210 simply don't cut it. The GeForce GT 630 GDDR5 (also known as the GeForce GT 440 GDDR5) is barely able to deliver playable performance, and the Radeon HD 6670 DDR3 only fares a little better.
Nvidia's GeForce GT 650 and AMD's Radeon HD 7750 are overkill for this level of detail and resolution, but we'd rather be pushing these settings higher anyway. We are gaming on a PC, after all.