My proposal is to replace ETG with oETG after the death of Flash, and then build around oETG.
Continue the plan to graphically overhaul oETG. Make the game more aesthetically pleasing, more user friendly, and more marketable. Begin using oETG in its current form for PvP Events here, including War.
Additionally, I propose the following steps as means to that goal, some of which may be controversial:
Rebrand oETG as Elements: [subtitle]. Market it as a spiritual successor to Elements. A rebirth, a defiance against obsolescence, a new era. Publicize the game in appropriate places.
Create a team to facilitate future development (balance, design direction, worldbuilding, programming, etc). The game can still be open source, there's no inherent issue with that, and it would allow for a modding community, but it would be essential that there's a central version of the game that's being supported and actively developed (and also - anti-cheat measures may need to be considered, for events with significant prize pools).
I think doing this properly would result in the steady growth of the community.