It's only expensive when compared to products churned out by massive megacorporation with economies of scale on their side. This device was made from scratch by a very small company.
The Arduboy is $60. I don't doubt this thing is more capable that the Arduboy, the hardware is probably nicer, but they're both tiny fidget toys for small games- and one is 4x pricier than the other. So it's not like cheaper indie handhelds can't exist.
Apparently the Arduboy is based on the ATmega328. Is writing code in C/C++/Rust fast enough to write full-motion graphically/logically complex (if graphical complexity is even possible on a small display) games on the system, or do you need to implement large chunks in assembly code?
It's only expensive when compared to products churned out by massive megacorporation with economies of scale on their side. This device was made from scratch by a very small company.