Possible: HTPC (small form factor) AND gaming?

Something you can buy off the shelf and play games dunno, did a quick google but didnt find anything.
Went to ebuyer and did a quick spec, for under £600 you could build a good HTPC with BluRay, 1TB Storage, digital receiver and an ATI 4850.
Obviously you would want to research each part a little more thoroughly first but it should give you an idea on what you can get for that kinda $$

Lian Li PC-V350B Black Aluminium Cube Case - No PSU £85.98
Corsair 450W VX Series PSU - ATX12V v2.2 £58.15
Sapphire HD 4850 Toxic Edition 512MB GDDR3 Dual DVI HDTV Out PCI-E £142.98
Samsung SpinPoint F1 HD103UJ 1TB Hard Drive SATAII *32MB Cache* - £79.99
Gigabyte GA-G31M-S2L iG31 Socket 775 mATX £42.21
OCZ 4GB (2x2GB) DDR2 800Mhz/PC2-6400 GOLD XTC Memory Kit CL5 £42.99
Intel Pentium Dual Core E2220 2.4GHz (800MHz) Socket 775 £59.25
Hauppauge WinTV-Express TV Tuner PCI card £25.65
Sony BDU-X10S Blu-Ray BD-ROM SATA Black Internal - £54.95
TOTAL - £592.15