Konami registered the title “Castlevania Advance Collection” with the Australian Classification Board on June 18th, 2021. The author is listed as “M2”, who are a Japanese studio that worked on the Castlevania Anniversary Collection and the Contra Anniversary Collection.
No other info has been revealed including which Castlevania titles will be on this compilation. There were 5 Castlevania games released on the Nintendo Game Boy Advance from 2001 to 2006, and they began what was without a doubt the most exciting decade for the franchise that also included great Castlevania titles released on the PS2 and DS.
The 5 Castlevania GBA games were Castlevania: Circle of the Moon (2001), Castlevania: Harmony of Dissonance (2002), Castlevania: Aria of Sorrow (2003), Castlevania Classic NES Series (2004), and Castlevania: Double Pack (2006), which contained Harmony of Dissonance and Aria of Sorrow.
It is safe to assume that this Advance Compilation will at least include Circle of the Moon, Harmony of Dissonance, and Aria of Sorrow.
The Castlevania Advance Collection is listed as Multi Platform. It is unknown at this time if that means Switch, PS5, PS4, PC, etc. Either way this will be a great way for fans to relive the Castlevania GBA era on a new system, and for newer fans of the series to get a chance to play those amazing titles that continued the Metroid style gameplay which began with Castlevania: Symphony of the Night.
Stay tuned for more details on the Castlevania Advance Collection as they are revealed.