For the sake of preservation, I have no qualms about them getting re-released at all. I guess the Advance games have some publishing/distributions issues to clear and bringing the Rush titles to a non-handheld/dual-screen platform may be a bit difficult; but I imagine the main culprit to their lack of modern availability is the current corporate aversion of re-releasing anything from the 2000s era of Sonic (post-SA2/pre-Colors). Regarding the games themselves, I'm kinda of the thought that the Advance series is a steady decline across each game (kinda good --> average --> kinda bad), and Rush is...fine as a a standalone game/series. (Its gameplay being used as the new "default" for 2D Sonic gameplay over MD gameplay, not so much.) Never played Rush Adventure so I can't speak for that. Advance 2 confuses me though in that I think its better than Advance 3, but I got further to completion in 3 than 2 (I stopped around the game's most maligned zone, Sky Canyon, so that probably plays a role). In terms of continuations, I would very much like to see a new installment of the Rush/Boost gameplay--provided that the developer's goal is to actually reassess what's been done with it and refine the playstyle, instead of using it as more gameplay filler to avoid developing fully 3D levels for the 3D games. The handheld cousins of ST's console games and the later Boost games have arguably run it into the ground; but (much like how I've felt with the 3D Boost titles) I think you could streamline it into a format that cuts down on its weaknesses and better plays to its strengths. Advance however, I feel that's enough of a collective mess of priorities and ideas (with 1 being neo-MD, 2 being proto-Rush, and 3...being 3) you're better off with a spiritual sequel; or a reboot if you had to continue the Advance name. In particular, I feel the hypothetical successor/reboot should develop Advance's special qualities into a new style of 2D gameplay that has neither platforming or speed as the main focus. Based on the Advance series' secondary moves and the adjacent Battle spinoff, I'd say action/combat and/or exploration would be a more ideal goal.