Even with Javascript, there should only be a 10x performance penalty at worst, and getting to 2x penalty is feasible. We do need to scale based on screen size

Even with Javascript, there should only be a 10x performance penalty at worst, and getting to 2x penalty is feasible. We do need to scale based on screen size though - copying pixels around is expensive. But a low-end machine from 10 years ago should be mandated for all developers.