Postby Emral » Sun May 16, 2021 6:07 am
SMBX always had a tendency to perform badly when a lot of items were used (levels with 10000+ blocks from back in the day were very lag-prone when sparkies were used, for instance). The new additions in SMBX2 can certainly have a similar impact on low-end hardware, though if you were to point at a level that lags for you, I'd need to investigate it in detail to be able to tell why that is, since there are plenty of different ways for things to be unoptimized now that every level can use complex basegame features, or custom code.
A fairly common cause for lag I notice on particularily low-end laptops is lag whenever GPU-utilizing features are used, like shaders, since those laptops tend to not have dedicated graphics cards.