For those who've played RTS, it's common knowledge to use resources ASAP. But it can be unintuitive for other players. That's why I've added a resource cap from the beginning to nudge players into spending resources sooner. That's why it's also a huge part of the UI.
However, there have been instances where players get a lot of resources at the same and forget they're already maxed out. So I've added an animation and sound as a reminder once 75% of the cap is reached. (Only happens up to once every 15 sec so as not to be too annoying.) Also, the resource display now flashes faster the closer to the cap the player has reached.
During testing, there were instances where players would finish harder areas first and find other areas too easy. I've placed a DANGER rating on each level to add a bit of clarity to the intended difficulty throughout the game.