This was taken from a post written by mike89. Link to the original thread: https://forum.speeddemosarchive.com/post/de_blob_looking_for_other_runners_info_on_scoring_system_inside.html

There are seven main areas in which to build up points: completing challenges, enemies, completing blocks of buildings, "chaining" buildings, chaining sets of Graydians, transform engines, and miscellaneous sources of points.

CHALLENGES Challenges are worth 3125 points on completion. This appears to apply to all challenge types (brown, blue, green, orange). For brown challenges, you also have to paint a "landmark" with a certain amount of points of one colour. These appear to be scored at 50 x the number of paint points (so a 30 point landmark is 1500, 50 point is 2500, etc).

CHAINING The chain system is pretty simple: whatever type of chain you're working on (buildings, enemies or Graydians), you get an additional multiplier if you can link another one in a short space of time. For buildings in particular, this means that you have to reach another building before Blob reaches the ground. The multiplier increases linearly and caps at 8. The multiplier will stay at x8 for as long as it can be maintained, but will not exceed it. Chains cannot be mixed. You can chain different types of enemies at once, but if you are collecting a set of Graydians and then attack an enemy, for example, the Graydian chain stops and a new enemy chain starts.

ENEMIES The points enemies give are shown on screen. Most enemies give 50, but Leechbots give only 25, for example. These chain in the same way as other items chain: the multiplier will never exceed 8, but you can continue to get x8 for as long as you can continue it. Enemies also cost a certain amount of paint points to kill, basic enemies are worth 1, coloured enemies are worth 4 of a specific colour, Heavy Inkies are 10, turrets are 50, and the Ink Tank takes the whole complement of 100.

BUILDINGS You get 100 points for painting a building, plus the usual multiplier for as long as you stay off the ground. Block bonuses are easy, they're displayed on screen. The total is 100 x number of buildings x number of colours used, so more colours is better (note that invincibility mode switches you between colours so this is a really good time to build this up!) One thing that is kind of related to this is that it is possible to increase the amount of points you get from a block, even after it's been completed. If you take an additional colour to an already completed block, you'll get a bonus equal to the value of the block (you'll see it on the right of screen). This also breaks other types of combos, and explains an odd case where I had spotted large bonuses in the middle of collecting Graydians. Invincibility (as dispensed from the "paint tankers") actually goes through all seven colours in a set order - it cycles through in the order green, blue, purple, red, orange, yellow, brown. Because of the timing of the colour changes, it is actually possible to double up on chains, eg. if you jump onto a building at green, you get 100, then 10x2 when it changes to blue, then 100x3 on the next building.

GRAYDIANS Graydians give 50 for the first one, then they can chain if you are quick in getting them all (again, up to 8 max). There's no difference between Graydians that hang around loosely in some levels and those which are dispensed from completed buildings, and they can all be chained at once, but as stated above, painting a building a different colour will break the chain.

TRANSFORMS Don't give any solid amount, instead it's based on the cumulative total of all the painting that it does automatically for you. This figure generally works out somewhere in the 2-3k range, but most importantly, it's "free" points - during the animation the timer is not running, so it's a few thousand points for no time cost.

MISCELLANEOUS Billboards are worth 500 points each, and cannot be chained. There are also items composed of red, yellow and blue strokes, which are worth 1000 points each. These can be worth collecting if the detour is small, but there typically tends to be more points in chaining.

Just as a quick point of comparison, for route planning: 4-building combo: 1000 8-building combo: 3600 8-Graydian combo: 1800 16-Graydian combo: 5000 Challenge: 3125 Energy item: 1000