Yeah you really don't want to rely on the Intel HD 2000 or Intel HD 3000 for playing games. Core i3 models ending with the number "5" have the faster Intel HD 3000 core like the Core i3-2125. All models ending with the number "0" has the slower Intel HD 2000 core like the Core i3-2100.
I tested the Intel 3000 graphic core on my Lenovo IdeaPad Y470 with a dual core i5-2410m and nVidia GT 550m. The resolution is 1366x768. Fallout 3 was actually playable with a mix of low and medium settings. I would say mid to upper 20s in terms of frame rates. Crysis was only playable with low settings and the average frame rate range between 18FPS - 24PFS in the 2nd chapter "Relic". Everyone knows that the final battle in Crysis is extreme rough even for power PCs. I would guess playing that final chapter with an Intel HD 3000 would have resulted with at best 7FPS - 9FPS.
Mass Effect 1 seems to work okay with medium settings... until it crashes. Weird, it only crashes when using the Intel HD 3000 graphics core, not when using the nVidia GT 550m.