M2 just released the official trailer, coming "Early 2022 Probably"
https://youtu.be/4cAHDOUXC34
Looks good! Much more polish than I was expecting, as they'd talked about it like it was some kind of hobby side project or something. After GG Aleste 3, there's every reason to be excited.
Some additional details, courtesy of Aleste Wiki:
The game was first announced in November 2018, being developed by M2 to commemorate the 30 year anniversary of the franchise. In June 2019 the game's official title was confirmed, with the character design of Ellinor Waizen by illustrator Eiji Komato also being shown, while the new player ship, the Aleste Dragoon, was revealed during the Japan Wonder Festival in July 2019. Additional information about the game was unveiled in September 7, 2019 during a special event in Akibahara, Japan, such as the game being designed with console-style difficulty in mind, as well as the ship's design being affected by the currently equipped weapon.
Staff
Naoki Horii - Planning
Highma Fuyuno - Planning, graphical design
Masato Yamanaka - Programming, game design
Keiji Takeuchi - Music and sound design
Eiji Komatsu - Character design