So, I'm on another play through of the game and I'm enjoying it just as much as the first. This time, I tried something different. I made a personal rule that I HAD to complete all surface portals before the core portal could be unlocked. My last game I landed in areas next to portals so that my base's power could be used to power up the portal quickly. This has been a bit more tedious but I still enjoy it. I'm finding myself trying to optimize mobile power generation in ways I never did before. This got me to thinking how some subtle tweaks could increase replayability: 1) Add option for how many surface portals have to be enabled before core is open (defaults to 1 for normal mode) - for the moons it could be rounded down? or both? 2) Option for indicating landing areas to be away from surface portals (defaults to false). This forces the player to figure out a way to get the power to the portal without extenders (or at least without a butt load of them). 3) Option to randomize the final ingredients of the planet cores (same ingredients, just move them around a bit, so I have to figure it out... honestly, if this could be a special recipe I need it would be even better). Perhaps the blueprint is downloadable from the center portal once you gain access. 4) Ability to apply a multiplier to tech costs (for example, I may want to pay 2x or 5x the amount of bytes for researching things to slow my own progression down). I went to Glacio first this game and I am almost done with the entire tech tree. 5) Could have an option for how fast Oxygen depletes. I think these would be simple... 'mutators' that could be added to the game pretty easily and really changes up the game play.