Graphical-
+Option to toggle between Classic SK graphics and New SK graphics.
I love the art style of the old graphics for materials. It would be interesting to see them again.
+Option to turn off red glow around screen when being hurt, or when below 30%
I hate this glow. It hurts my eyes. (ALREADY FIXED)
+Option to turn off fog in levels.
I love the look of the game in high quality graphics, but the fog hurts my eyes.
Minerals-
+Bring back Player Made gates.
For those of you who don't know, before the Battle Sprites were implemented, the minerals were used to create each gate. A combination of 2 minerals would each create a stratum. The reason for this being removed was because only Blue and Green minerals would ever be deposited, leading to it almost always being freeze stratum in most arcades.
+Make Battle Sprites for Blue and Green
I always disregard Blue and Green as useless, so I never collect them. However, new sprites for these minerals would make them useful.
Rarities
+Make all of them more common
Nothing's funnier than going through 8 treasure vaults, 8 danger rooms, and 8 arenas to find exactly 0 orbs. It's hilarious!
+Fire Crystals
Remove them. Just kidding, don't. However, make them more common, and make the dispersement of which ones you can get in each depth better. For example, I would remove Warm fire crystals entirely from Tier 2, and make Radiant fire crystals more common in earlier depths.
That's all, folks.
Oh yeah,
Levels-
+Make Deconstruction Zones less bland
They are just gremlin spam that could easily be replaced or be changed to something better.
+Make Compounds less annoying and/or more rewarding
I hate these stages. Maybe more rewards for my blood would make it so I don't wait another 8 hours for it to cycle to the next stage instead of just doing the compound.
+ Make the Arcade more varied.
There is almost always either a Construct or Gremlin stratum in each gate. I'd first of all, make the Construct and Gremlin stages more distinct from each other. Second, I'd either A. Bring back gate construction again, or B. Make certain themed stratums less likely to appear if the gate right before it has the same stratums.