Taken aback
A word that captures the idea of a "nice surprise" and starts with "mr" is "mirth." While it typically refers to joy or amusement, it can imply a pleasant surprise in a broader context. Another option is "merriment," which conveys a sense of fun and enjoyment, often associated with unexpected joy.
Perplex
Another word for shock in the context of surprise is jolt.You could also use the words awe and excitement.
Pop quiz
This weekend I had some unsupecting guests visiting.
In our family, we call them "refrigerator surprise."
Mesmerized,flabergasted.
Another word starting with g is gloominess
The word is starting! Starting, staring, string, sting, sing, sin, in, I.
oho, aha
extracted
Finish is another word for completion starting with the letter F.