Either it is only accepting a subset of TypeScript, or it is still interpreting the parts that don't have enough types. Given other comments here it sounds like the later.
What it can actually compile is a subset of well-behaved typescript. For anything else it bails out and asks you to ship a JS engine (albeit, not NodeJS) again.
Either it is only accepting a subset of TypeScript, or it is still interpreting the parts that don't have enough types. Given other comments here it sounds like the later.