Moodle themes are often termed as boring and without life but if you will have a look at this Moodle site then you will feel a freshness and a lot of new features implemented without core hacking.
The site https://learn.unitedforwildlife.org/ is designed by Floream and it includes a lot of work on these plugins:
- course formats
- availability restrictions
Here is an embedded slideshare presentation shared by Thomas Bell about “Transforming Moodle – United for Wildlife Implementation Case Study”
Here is a link to the Moodle forums thread discussion about this beautiful website: https://moodle.org/mod/forum/discuss.php?d=314373