I'd put a Forth interpreter under an esp32 laptop with some disk additions:

https://github.com/howerj/ffs

I learn with DOS an such under Elementary. So, kids today can do the same.

No, no Subleq, but:

- 32MB disk

- 256-1MB RAM

- 64x16 screen

- Forth block interface and prompt

- Printing? Basic PostScript can be set fast from Forth.

No internet, just Forth. The basic of loops, and even basic 'algebra' with the 'fruit balancing puzzle'.

Games? Sokoban under Forth, with a few blocks wasted with code and levels. It would fit under 110KB. 'Adventure' (Collosal Cave) fits under 150KB. Tetris, the same.

Gopher? Ok, doable, even a basic Gopher client too; I'm doing one with JimTCL, and in Forth with a proper stack I'd set one menu based such as:

    1 item
    2 bar bla bla
    3 baz

Enter the number, you enter the link. Easy, no issues.

If you can code a Gopher client, a MUD one it's almost at ease.