Because the artist who was making the art originally stopped drawing altogether and stopped answering emails. I couldn't find new artists that had good quality, and the drawings cost around ~$200 each. There are currently around 1000 images in the game and we're still adding a lot more artwork. If you would like to sponsor us $200,000 we can find a new artist and replace all the current artwork. It was taking ~3 days to 1 week per image for the previous style of artwork, so in 3 years we might be able to release.