Best Computer Science Course Emphasis


I'm current at a stage where i need to chose if i go down a more computer oriented course or a more mathematics based university course. 

Although i don't have a clear job in mind once i finish my education i would quite like to go into a field akin to language or game engine design. 

By computer science i mean learning about the underpinning of the computer and how it works, whereas by Computer Science AND Mathematics i mean 50/50 split between computer science and undergraduate level mathematics.  

My question is "For those tasks is it better for me to go into a purely computer science based course or one with high emphasis on mathematics?"


Many thanks from here in the UK


p.s. its maths with an "s", from the Greek "Mathematica" where the "a" at the end meant plural... just saying =D