After opening the scoring in the eighth minute, Rueda's men were forced to come from behind late on to earn a draw on Wednesday after Wayne Rooney and Rickie Lambert had netted for England.
Michael Arroyo's 70th-minute strike from distance earned Ecuador a draw in Miami, although Antonio Valencia was sent off late on after clashing with Raheem Sterling.
Ecuador have drawn with the Netherlands and England in their warm-up matches, and although they were also beaten 3-1 by Mexico, Rueda sees plenty of positives ahead of the opening Group E clash with Switzerland.
"All the friendly matches we played were difficult, but let us learn (from them)," he said. "They (friendlies) have been three major tests, but the real challenges will be in the first match of the World Cup.
"Except for the injury to Segundo Castillo, the balance was positive. I hope the injured players recover well.
"England demanded a lot, but the defence of Ecuador responded well."
The game ended on a sour note with the dismissals of Valencia and Sterling following a 79th-minute from the England substitute, with Valencia apologising for his actions after the match.
He said: "To the Ecuador fans, the coaching staff and my team-mates I apologise for my reaction."
