My main ideas were:
* a much needed Jimmy redesign (one that brings Jimmy closer to TS anatomy and makes him look less weird)
* a mixture of TTS and MOTAS aesthetics, the menu being MOTAS and the shop background being TTS
* sweepers with the TTS 'clock' designs
* speed stats in the Status box which I think would be useful
* HD res
The amount of lineart and doing my best to balance colours was a pain in the ass. I still don't do backgrounds but doing any would hopefully lead to more inclination to draw them more often.
I never put much myself into thinking about what a third BLiNX game would be, but I have to admit I like a lot of your ideas.
I'm not sure what the right thing is to do with Jimmy, but combining the first two games' aesthetics works fairly well, I think. I feel like the first game had a lot of personality but relatively little done with it (the menu navigation and whatnot was quite minimal), whereas the second game expanded outwards with a less unique aesthetic. Building off of the ground the second game covered while reintroducing the character of the first is a good way to preserve the series' roots while maintaining some of the "maturity" (as in having been refined, not anything age-related) that came with the second game's design. Interestingly, I think the modern trends towards really clean looking designs with pretty colours would actually suit BLiNX rather well.
I don't know if I'd kick the guitar-inspired sweepers to the curb entirely, but I definitely wouldn't want to let go of the first game's clock motif, either. I think coming up with a "next generation" of the original clock-based sweepers (with some more variation in shapes but keeping the clean curves instead of all the hard angles in the second game's sweepers) would be a good compromise and let that part of the design grow while still acknowledging its original identity. No idea why there was no speed stat to be seen in the second game, for that matter.
You think at all about the tone, though? I think that's the other big conflict to resolve between the first two games, aside from the aesthetic. The second game not only took itself a lot more seriously, but it also gets a little grimmer than expected at some moments with the somewhat realistic depiction of firearms (the Winterfield and its headshots being the big one, of course) and pondering of whether everyone will actually survive A000. The first game generally wasn't that serious outside of the opening (not that there were many other opportunities to be).
I like the idea of a new generation of clock-based Sweepers, alongside bringing back some TTS and MOTAS sweepers. Not sure if I would bring back the idea of "skins" like with the TS-4000 series but it would add some customisation.
My idea for the game's tone and conflict would be one world to multiple worlds, just not the whole universe because I don't think that would work again following MOTAS. Perhaps add stuff like showing the state of the world as it gets better or worsens to make it more serious.
Guns probably wouldn't have a reason to be added in unless you wanted to add gun-related mechanics or pick up weapons from Tom Toms you encounter.