The solid sprite routine in SMW sets $C2 to 1 if it was previously 0, when the sprite is hit from below. However, a few sprites were overlooked which can unintentionally change state by being hit from below:
- If a normal Bowser Statue is hit from below, it'll start shooting fireballs.
- Hitting the Boo Block from below when it's semi-solid will cause it to immediately become fully solid.
- Hitting the grey castle block sprite from below when $C2 is 0 (where the block will be stationary before moving left) will cause it to immediately start moving left.
This patch fixes this issue by excluding these sprites from the solid sprite routine's $C2 check.