So many new flavors, so many of them delicious...
I, myself, am rather swamped by this influx, but if Hudson is to see this, why not give it a shot?
As a fan of the trilogy, especially of its contemporary, yet refreshingly grit-free storytelling, I can list five suggestions right of the bat, which involve a Setting, Plot Point, the Soundtrack, some Mechanics, and newer forms of Interaction.
Setting- In sprawling through here, I can't distinctly remember if anyone already suggested Time Travel. It's a risky endeavour, but I'm thinking that perhaps a hapless, or even renegade, race discovers the secrets behind time travel, yet unwittingly make way to the time before the Asari discovered the Citadel, or even before the Mass Relays' discovery. With these travelers as the only beings that could even be capable of interstellar travel, they find themselves stranded temporarily, yet still able to piece together a more succinct puzzle of what the Protheans have left behind. This decision could either catalyze their discovery, or inadvertently lead to widespread chaos.
Plot Point- Taken from a First-Page-Suggestion, maybe Andromeda and other Galaxies can be involved in what's already such a melting pot. I leave this to the liberty of the in-house writers, but I'm thinking of either having life even more complex than what's already been imagined, or even leaving such galaxies open as lifeless, but rich paradisos ready for the taking. Somehow, it could be as well-integrated as Spore's Galactic Mode, with just as fertile tools and frontiers available to explore and be affixed as just as mysterious a plot point as the Protheans to begin with, though the mystery sprawls beyond the confines of space and time to practically metaphysical reaches.
Soundtrack- From my perspective, I see the entire trilogy's soundtrack as this: Hans Zimmer, Brian Eno, Klaus Schulze, and Prog Supergroup U.K. meet for a Stellar Powwow. Great tunes, great atmosphere; I would definitely like to see more of this, though with just a few more flourishes of ambient music that's both energetic and perhaps isolating. Just for further reference, I would recommend Eno's "Apollo" Soundtrack, Several works by Schulze ("X," "...Live...," and "Mirage" come to mind), and U.K.'s two studio albums ("U.K.," & "Danger Money"). In short: Electronic Ambience blends with Eclectic Energies and Odd Rhythms, per the situation.
Mechanics- Everything might as well be based upon Thermal Clips and Conversation, but it rightfully bears repetition. As much as I got a kick out of the Action-Based Gameplay of the latter two Entries, the first still holds its own through Exploration. As such, I think it would be prime to find a balance between Freelance Exploration, Dynamically Heated, yet Balanced Encounters (no matter if scripted or otherwise), and More Diverse Conversations. If a proper boundary can be maintained, maybe vehicles can make a comeback; they won't even have to be limited to the Mako or DLC-Hodgepodge such as the Hammerhead. As such, maybe expansion can be made to Starfighters, drawing influence from the successes of Totally Games' "X-Wing vs. TIE Fighter" Series and (ironically enough) Origin Systems' "Wing Commander" Series. Drawing back to Bioware's past glories (i.e. Baldur's, Neverwinter, KOTOR), maybe more stat-crunching could be made available for the more strategically-minded player, while keeping enough foes to ensure an ever-mounting challenge that lives to the premise's promises. As an afterthought, maybe weapons can be placed in just as serviceable an inventory as ME3, though with more opportunities for customization and perhaps bringing maintainence as an integral measure of ensuring survival. As for ammunition, a sweet balance was also struck through ME3, with dead-on accuracy and callbacks to the thermal-clip-free system of ME1. Perhaps more can be done to intensify the negative consequences of just firing aimlessly aside from thermal clips and overheating. Perhaps this balance can be kept to ensure just as fair and challenging an experience as possible. Yet another afterthought, Powers of all sorts are very well-balanced and enjoyable, so maybe some work can be done in ensuring diversity, but I see no other ground to cover.
Interaction- And in speaking of Bioware, can it get any better on the sidelines than with the dialogue? I admire the previous games with the conversation wheel, but maybe a transition can be made to include even more options to choose from; still generalizations to choose from that are fully acted, but ones that become very much alive in allowing more elucidation and outcomes than just the stagnation that could be found, say, sometime after a character's loyalty mission had been completed. Even with this harrowing extent of storytelling, much more can be done to make the entire cast (including extras) more diverse, engaging, and able to sympathize with.
Other Pointers and Farewell- Quite a bit to digest, but I grew quite a heart for this series. Much like many of those who have already voiced their interests, I wholeheartedly believe that much can be done with a clean slate. It just has to be taken in knowing that with all these newer adaptations, the series already has an impressive legacy that mustn't be wholly overlooked. How it can be integrated remains a challenge, but so does the culmination of ideas that sprawl across these 200+ pages. To Howard, may the best come to fruition in this new entry from your behalf and BioWare's. To all, feel free to comment on anything; I'm open to criticism of all sorts, but thank you for including me in such a diverse, intelligent, persevering community.
Keelah Se'lai.