[Vlad_the_Inhaler]

Yes, there is a lot more slang in 'British' English than in American.

BrE uses both High School and Secondary School, and both Further and Higher Education. I've never heard anyone in the UK use the phrase 'class fellow', and a drugstore is a Chemist's - Chemistry is the science.
Mad also means angry in BrE.
US and BrE have some differences in past forms of verbs - learnt/learned got/gotten etc.
One of the most obvious differences in US English to a British ear is the ommission of and in numbers, as we say one hundred and fifty, two thousand and twenty etc.

If you are going to include pronunciation, it may be a good idea to mention the enormous difference in regional accents in the UK compared to the US. People from the Black Country (Wolverhampton, East Birmingham) the North East, Scotland, and some other areas have accents which fellow Britons find it hard to understand.