it depends on your comfort with (enthusiasm for) electronic design. this is a really good starter project in general.
multiplexer, use some 4051 chips. each has 8 inputs. connect one 4051 output to an single ADC input.
so, to do 64 analog inputs, you’d use 8 ADC channels.
three digital outs select which 4051 pin to read (all the 4051 chips). so you can “scan” pin 1 of all of the chips, then switch to pin 2, 3, 4…
the code will be pretty simple.
what form factor are you looking at?