Just under two months ago, it was announced that development of Ubusuna, the spiritual successor to Treasure's shoot 'em up classic Ikaruga, had been cancelled. Development had actually begun as early as 2014 under the direction of Ikaruga creator Hiroshi Iuchi, and M2 was involved in the project as the publisher.
Following this disappointing news, Iuchi left M2, but the publisher wrote in an open letter at the time that "Mr. Iuchi has not given up all hope of completing 'Ubusuna,' independent of M2", and apparently, it seems that hope is still alive. Via his website (thanks, Automaton), Iuchi now shares his perspective on what happened to Ubusuna and why it has taken so long to finish it.
Among other things, he explains that the team rarely had the chance to work on the game because there were frequent breaks when they were assigned other tasks, and there has also been an excessive pursuit of perfection. Initially, he accepted the game's fate, but colleagues and companies have shown interest in completing the game, and he now writes that work has resumed without M2's involvement (translated using Google Translate):
"I don't know what the outcome will be, and it may not be something that can be resolved immediately. However, we are working hard to deliver 'Ubusuna' to all of you who have been waiting so long, so please continue to wait and see. The entire staff will do their best, so we would be very grateful if you continue to support us."
Iuchi also notes that Ubusuna is a more forgiving action game than Ikaruga, and even though it's been in production for a long time, its core remains intact and is still entertaining:
"Furthermore, even though Ubusuna itself is a somewhat unique shooter and difficult to adapt, the concept itself hasn't changed at all since 2006, and there are no issues. I don't mean to sound boastful, but even after playing the game as it is now, I think it's pretty fun. (I think it's probably easier for most people to play than Ikaruga.)"
And with that, we're back to square one. The graphics and similar assets created during his time at M2 belong to the latter, and it remains to be seen whether he'll be able to buy them back at a reasonable price. Ubusuna will hopefully be released in due time, but don't count on it happening anytime soon.