Unfortunately, if you want the newer worlds I am designing I am afraid there will be a wait. But I will try to pick up the pace with finishing them. However, if you are interested in some old worlds that have never made the addons list, would you consider these:
Halloween Horror 13 - RR: https://yadi.sk/d/hdffbe-93Moga3
Back in the days when the forum was still around, I do not know whether you would know this piece of trivia or not, there would be annual world building contests held for a particular theme. Starting in August/September and ending in October, the Halloween Horror theme was one of four where world builders or onlookers would suggest names for levels and then there would be polls where nine of the most popular names would be chosen and people would have to design levels based on those names. Having only been tested once, this is one of the lesser known worlds of the Hamumu community designed by me as it has never made it to the addons page due to lack of testers. However, if you would like to include it in your game but you do not like the title, I would not be offended if you would rename it.
World of Lunacy: https://yadi.sk/d/QZetpaH33MogZz
Another lesser known world, but it was designed by a friend of mine from Brazil. It is one of those worlds that had pushed the editor to its limits with some very enjoyable and challenging levels.
Yearly Merge I: https://yadi.sk/d/EEp1vN703MogRC
This yearly world merge has levels from four authors including me, and it was initially supposed to run for a few more years. However, due to lack of new members in the original hamumu fora and the reality of university of career time investments that the old members had to be responsible for this was the only world produced in of the series. Though be that as it may, it has some quite challenging gameplay and the levels could be considered some very good gems. Again, if you would like to include it but do not like the name then by all means you can rename it. I do not mind name changes that much, as I would prefer to see these worlds put to good use or appreciated than forgotten forever.
Wish me luck in developing further worlds. I too have become one of those members who is bogged down with university and life-related responsibilities, however I will try to finish as many worlds as possible during the holidays as I do not want to end up being a Leonardo Da Vinci. I hope you find these worlds listed enjoyable.