Alien concept art

I have been thinking of shifting Polly forward a few centuries. These are a couple of concept alien races I have knocked up.
The one on the left is a semi aquatic flatworm-type creature that can only get around in the modern city with the aid of a mechanical walker (mechanical arms help for dealing with punk kids )
The one on the right was traditionally a fast and agile open planes hunter. They are sightless and instead rely on echolocation and bio-electrical fields (like sharks) to navigate their way around. The feather-like appendages on their heads are the receptors they use. They cannot see the visible light spectrum and so are not particularly interested in clothing but they love metal jewellery that transmits, reflects and distorts bio-electrical fields.

I am thinking the world will be a very capitalist society where police are ineffectual and business is cut-throat, leading to the rise of many private military and security firms. (plenty of work for a scoundrel like Polly )

Tell me what you think! All criticism (of artwork and concepts) is VERY welcome. Any cool ideas you have will definitely be considered as well.