I love the feel behind this concept. Brings back the colourful, magical, fantasy sense you get from the woodland.
Nice cap on the one on the left! Reminds me of a starry sky. Perhaps it's magical? A neat effect could be a sort of parallax movement, where the sky doesn't shift at the same speed as the rest of the mushroom. The cap would look like a portal into the sky.
The dark one seems to have a stonelike, or perhaps ashen, texture. It feels like it the sort of thing you'd encounter in a volcanic region. I'm not sure that there's any area that would be well suited to that at the moment. Perhaps we should see if anyone's around and make one? A volcano area would be a pretty awesome thing to have, though that would be no mean feat. Maybe we could add something to the west of the mouboo hills? I'll have to look around to find the old plans, but from memory it was going to be a very cliffy area eventually reaching the sea.
Regarding licensing, it's a touchy subject at that moment. Sorry about the upcoming wall of text, but it's all too easy to gloss over the issue, and I think it's important to explain the situation that TMW is in, why it has to ask for what it asks for at the moment, and how people are working to fix things.
A long, long time ago, TMW decided to require GPL for all artwork. GPL probably wouldn't have seemed like an unreasonable choice at the time. After all, it's a free license that ensures that things stay free, that people can use it, and that any credit the author wants is preserved. Unfortunately, GPL has lots of subtle problems when it comes to art. Definitions that are clear and obvious for programming are unclear and could have many different interpretations when it comes to art. That's why a lot of people are trying to get all the people that have contributed art in the past to also let TMW use their works under CC-BY-SA, which is a far better license for this sort of thing.
GPL and CC-BY-SA do not play nicely with each other. Both have copyleft provisions, which say that if you make something new from a work under that license, then it must be released under the terms of that license. There is a good reason for this, as it ensures that a work will stay free.
But when you have one work that is only under GPL, and another that is only under CC-BY-SA, and want to combine the two, you're in a bad position. [
CC-BY-SA is what's known as "GPL incompatible"]. You can't just release the new work under either, because GPL doesn't give others the right to put derivative works under CC-BY-SA, and CC-BY-SA doesn't give others the right to put derivative works under the GPL. Since the new work is derived from both, this can cause people to get stuck.
So in order for people to be able to freely work with things, we need to be able to say that all TMW art is available under at least one a common license at any one time. But the only license TMW can currently do this with is GPL. So in order for people to be able to freely combine everything TMW has, TMW has to keep asking for new contributors to let us use their works under GPL as well, no matter how much we want to move away from the past.
When TMW has tracked down and got permission from the old authors, and replaced any works which TMW hasn't been able to get permission to use under CC-BY-SA with replacement works that TMW can use under CC-BY-SA, then TMW can stop asking for new works to also be made available under the GPL. Unfortunately, getting permission from everyone to use CC-BY-SA can't just happen overnight. There are a lot of people that have contributed to TMW over the years. People are working hard to fix things (special thanks goes out to Ali-G and Reid for all their hard work!), but until then, TMW is forced to ask that people let us use anything new under both GPL and CC-BY-SA.
I don't think anyone will mind if you don't want to release you work under the GPL now, and instead wait until TMW is in a position to accept works that are only CC-BY-SA. It's up to you, and nobody wants to force you to do something you don't want to do. But if you do want these mushrooms to be CC-BY-SA only, it limits what can be done.
For instance, I'd love to be able to search through old threads to see if there are any volcanic concept tiles around, open up GIMP, and place your second mushroom on top of them, and upload them to this thread so people can see how they'd look together.
But, (fair use aside, which isn't available in all jurisdictions) I can't do this. The GPL tiles would demand that the combined image be released under the GPL. But your CC-BY-SA only mushrooms wouldn't allow me to do so. The CC-BY-SA mushrooms would demand that the combined image be released under CC-BY-SA. But the GPL only tiles wouldn't allow me to do so. In the end, I wouldn't be able to do anything.
Sorry about the long winded explanation. I hope this helps to clear things up, and doesn't distract from your awesome new mushrooms.
---Freeyorp