https://www.lexaloffle.com/pico-8.php
For those curious above is where you can find Pico-8. You will notice a price tag there. That should cue you into the first problem, copyright. This isn't free or open source software.
Here are some specifications. They should bring up two more problems.
Display 128x128 16 colours
Cartridge Size 32k
Sound 4 channel chip blerps
Code Lua
Sprites 256 8x8 sprites
Map 128x32 cels
The first is "cartridges" are stored in .png format, so you will need a library to save and load .png files. Not trivial. The second is that the code is written in Lua, now you need a lua interpreter too. So you can have an interpreter in an interpreter so you can interpret while interpreting.
If you think about it, SmileBasic really isn't all that different from pico 8 but with better graphics and a different source language.
So could you make a pico 8 runtime in SmileBasic? Legally... not so much, not without permission at least. Technically ... probably but it would likely run slowly and require lots of coding hours.
You could probably port dozens of programs before you could make a working runtime.