İnfinite node 2 is not a traditional tower defense game where you place tower , do the upgrades, play the stages and that's it. You mine resources, get tiles and items, use custom maps...etc in addition to a lot of math which makes it special.
At the beginning, there will be a need for these resources & items, but later collecting them will be pointless and annoying, just extra numbers or things make lag and need to be got rid of. Finding a REAL need for these things which makes collecting them important and meaningful rather than useless & pointless is a big challenge. Actually, this is a tower defense game and has limitations, in other well designed none- TD games you often will never have useless extra resources because you can consume them to be stronger.

• Solution - my idea:
  As I said TD games have limitations so I am going for out of box idea and long term project:
  Accessory "strategic game", where you you can use every thing resources & tiles gained from inf2 to build your base and walls and your defense/attack army. You can find a meaningful task for everything even music tile. For example, if you use a base with 40% attack speed buff as your main base, and then suffered from invasion and successful attack by a player, and you were lucky enough not to lose your base, but because of this attack your base got injured and lost a few or lot of its buffs including ATS, which dropped from 40--> 17% , and now you need to repair it, you can do that by merging it with one or more than one base, so using a cheap base has the same buff(s) (ATS) could be a good idea. Also you may need a cheap base as a secondary base in places can only has low classification bases, so you will look for a cheap base with buffs fits your & your clan's strategy and support your main base. The same for portals, portals are the place which produces your army, low% difficulty --> cheap & weak units, high% --> expensive & strong units, so while building your base you will use a different % portals (low, mid, high) with different enemy type according to your defense/attack strategy. Barriers & teleporters are invisible to other players, so with well strategic design they can Disperse enemy's force and give a chance for all your towers to participate in the battle rather than suffering from concentrated attack in one spot.
  When you have an attack, you lose some tiles and others gets injured and need to be repaired, so you always need more and more tiles. Be careful! And don't put all your eggs in one basket by building over powered base with a lot of V tiles and defense towers. Sooner or later the other clans will know that and plan to crash you by a massive attack, and then you will be out of date after losing your tiles permanently.
  Resources will never be "much" or more than required, everything costs resources starting from building your army, defense towers, repairing processes, replacing something in your base with something new or changing your base design...etc.

So the idea basically is clans- based strategic game , each player establishes his own base and belongs to a clan, and fightings between clans...etc
Here, infinite node 2 is the source of all materials required to build the base, also the towers and enemy's types ideas & principles almost all of them 85-90% from infinite 2 with minimal changes as needed.

Ok I don't expect to see this in 1.8 :) XD, actually not even in 1.8.x. if you like the idea you have more than one year to plan slowly to be in 1.9 or after.

Best...