Kithros once posted this in beta:
Is there any chance of having artifacts that can be destroyed by creeper without losing the game? It could be very helpful for having optional objectives in a map to get extra points etc., or allowing maps to have multiple difficulties where you can only pick up one artifact (where the amount of points and resources vary) before they're destroyed.
I was thinking along these lines: wouldn't it be possible to achieve the same thing when the amount of points obtained by collecting an artifact could be negative? This means they will be subtracted from your score.
For instance at the start of the map there are 3 gems: red (+100 energy, -1000 points), green (+200 energy, -2000 points) and blue (+300 energy, -3000 points). The less energy you need to finish the map, the higher your score will be. The same could be applied to artifacts (i.e. finishing the map without the shield tech would gain you 2500 points). Of course on these maps it shouldn't be mandatory to collect the techs.
I think this would be rather easy to implement and allow us to design maps that are interesting for any type of player. It would also increase the replayability of maps.Edit:
If implemented it could be a wise thing to check for negative scores and set these to zero, so negative values won't cause problems in the game, database or score pages.