HTC Desire :: Playing Game - Phone Stuck On Frozen Loading Screen

It seems after only a fortnight or so from getting my new Desire (unlocked and unrooted) I've already run into a problem I can't seem to fix. I was running a game (I believe it was Asphalt HD) while on the charger when my screen went completely black and I found myself at the boot screen. It finished booting but then got stuck on a frozen "loading" screen. I restarted it and it worked fine, I assumed it was the app and tried another one. About ten minutes in I got another black screen and the phone started booting again. Only this time it would do the animated logo, then crash and try to reboot again, over and over until I pulled the battery. Only now it wont boot at all, it will simply sit on the initial HTC boot screen indefinitely. It won't turn off the screen or anything, just sit there in a frozen state.

So far I've tried removing the SD and even SIM cards, leaving it off to charge the battery, doing a factory reset from the boot screen, etc. But every single time, whether I turn it on normally or use the bootloader, all I get is the single "switched on" vibration and the HTC screen, and it just freezes there. I already spent quite a while waiting for this phone to arrive, I REALLY don't want to send it back to the store because it was bought through an importer and I'm worried it will take a very long time for any repairs/replacements. I will if I'm forced to but I would much rather find more methods I could try.