Sounds like the laptop is faulty, is the fan running? It is certainly overheating to such an extent the processor is slowing itself right down, maybe the heatpipe/heatsink isn't attached correctly in the laptop.
As for Dell not supporting you because there is no error code and the game is from a third party is ridiculous, you need to persist it with them and asked to speak to someone else if the first line script readers refuse to help.
Yeah fan goes. The support guy said the intel processor id utility was 3rd party and the reading it gives me they don't care about it because its third party. Dell are useless, I have to ring back on a weekday to speak to the supervisor.