Really, really impressive looking game in just about every aspect. Some of the assets in this game are so good that they look like they could be part of a complete project. Your presentation is probably the best in this game jam that I've seen. You did a really great job with this game, and you should be proud of it.
That said, since you gave me a lot of substance to work with, I have some constructive criticism too. Don't be intimidated by the length of this comment, I just added a lot of detail:
1. The timer should probably have been left out. Since the placements are randomized, the player doesn't learn much from failure. Plus, the atmosphere of the game is somewhat cartoony and laid back, so it doesn't really make sense to rush. You made a gorgeous, compelling environment, so don't punish us for taking our time while exploring it.
2. Speaking of the runes, I think you should have placed them manually instead of randomizing them. It's kind of cool that they're random and I know it was probably for replay value, but the issue is that players will enter unique areas that are somewhat hard to access, like the mountain, and not get rewarded for it. I got all the way to the top of the mountain, but I didn't get a rune. I didn't even get a good vantage point of the meadow to find more runes, because the trees blocked everything. The only thing I got was getting blasted by a little dragon at the top of the mountain! This would have been a good opportunity to reward the player for exploring.
3. It's not really clear what any of the NPCs are doing. It seems like some dragons are flying around, some are laying on their backs motionless, and some try to shoot you with fire. Are they good or evil? It would have been nice to distinguish them from one another. Also, I don't know if this is intentional, but the dog I found just says "I'll help you on your quest!" and does nothing but follow me around. I don't think he does anything useful, maybe I'm wrong though.
4. The environment, while beautiful, does look pretty same-y in most areas. Aesthetically this is fine - you did a really good job with it regardless. But for finding runes, it gets difficult, because it's hard to know where you were and where you still need to go. I wasn't actually able to get more than 5 runes, and I didn't drag my feet - I combed through the whole map a few times.
I hope you know that I only have this much to say because I was kind of inspired by this game. I've played some pretty great games in this jam, but didn't expect to see anything this good looking. Great work - let me know if you decide to add more features, I'd be happy to try them.