I think it's very viable and very fresh! Sometimes people are way too used to safe options and that always has its fair share of risks but I'd rather have this than so many of the samey style we often see 

Hey J�o, thanks for the comment, I've personally got no experience with game design so im not sure how viable my style or palette is.

I kinda love how rainbow in your face this all feels. It might not be traditional game design wise the best options, but in some ways I find it to be much more exciting. 

Thanks for the comment!

I wanted to keep the colour count low so I opted for using double outlines in the hope that it might remedy the problem.

I have a second, more desaturated palette that I could use for the background tiles so I might mess around with that and see if it help. 

Aw, man, this style gives me big Ultima IV for the DOS vibes. The only thing I can really offer as critique is that some of the bright spots on the background tiles compete with the foreground characters, most prominently with the bricks, although I suppose that may be just a product of the palette restrictions.

Other than that, I think it achieves your minimalist goal real well while keeping great readability on the characters' designs. Good job!