Sieve Spider
now uses the correct number designs as follows:
"spiky" numbers only for invincible numbers
"glitched" numbers only for weakpoints (legs)
NEW: "hatched" numbers instead of "spiky" for all sieve numbers.
as before, in easy mode, sieve primes having an additional small effect to indicate that they are primes
Summation Serpent:
fixed a bug, where under very specific circumstances it could happen, that the head became targetable even though some segments where still alive. Thanks to @agentimouton on Instagram for the bug report!
added the missing hard mode feature, where the summation serpent is charging the player for 3.5s at double its current speed after a segment has been broken
