It's a great choice for teaching programming, IMHO. As well as the official SDK supporting C and Lua there's also a "no-code" web-based game creator called Pulp

It's a great choice for teaching programming, IMHO. As well as the official SDK supporting C and Lua there's also a "no-code" web-based game creator called Pulp. For somebody totally new I would recommend starting with Pulp and progressing to Lua (which is very easy to read and fine for most games) and maybe even to C if they really get the bug. I've been programming for ~35 years and picked Lua so I can concentrate on my game design more than the programming. Also, developing for Playdate does not require a device — Lua/C require a computer and Pulp requires only a web browser — so it's essentially free to tryout hand at it.