I liked it, simplicity and all. I'll grant you that the ending didn't amount to much, but up to that point it kept me guessing. I thought we'd probably see beautiful Paris, and perhaps there would be more conflict between Jules and Jean (the boat love triangle trope). Vigo's writing and Michel Simon's acting were both sharp.
It also had several silent movie sequences. Most people probably don't even think about it, but the wordless montages of characters wandering around the streets is a silent era construct. It's fun to spot these silent sequences in sound films; John Ford is another director who used them a lot.