CREATE TABLE table_204_628 (id DECIMAL, "trial number" TEXT, "date" TEXT, "name of trial" TEXT, "celebrity/ies taking part" TEXT, "winner/number of stars" TEXT, "notes" TEXT)

what was the total number of stars given for the thunderball challenge ?
SELECT "celebrity/ies taking part" FROM table_204_628 WHERE "name of trial" = 'thunderball'
SELECT "celebrity/ies taking part" FROM "table_204_628" WHERE "name of trial" = 'thunderball'