Pickups should provide score

[benvinegar]

If we give the user an additional incentive to grab pickups – currently +health, +speed, and +protect – they'll be incentivized to move more around the map (and potentially forego XP), leading to a more dynamic game.

As we implement this change, we should monitor if pickups become an "overpowered" means of increasing score (e.g. don't want user to just run around the map picking up items / ignoring enemies).