You will get more feedback and help in something like the "Regional Maps" threads since those areas are for posting WIPs and designed for feedback but it looks good so far.

Not knowing the purpose it is hard to say for sure but if it's just a splash screen for a few seconds as the game loads or something you may not need much more.

That said, If you are going to have exceptional artwork within the game it would be a shame to stint on the openning screens which are what will give folks their first impression. You want to have some sort of uniformity I would think and so long as it's not going to look bad compared with the other art in your game you should be great.

Also, if you want more added to your map but are not sure how check out our Tutorial section for ways you might proceed.