Nimbly hammer out John Deacon’s bassline in "Under Pressure" and hold down to sustain Freddie Mercury’s soaring vocals in "We Are the Champions"

Question

Please help me figure out the meaning of the following sentence in the description of the app "Queen: Rock Tour":

Nimbly hammer out John Deacon’s bassline in "Under Pressure" and hold down to sustain Freddie Mercury’s soaring vocals in "We Are the Champions"

I am particularly confused about the meaning of the words "Nimbly hammer out" and "hold down to sustain".

Here is a description of the app from Google Play:

Embark on a musical journey to rediscover the story of Queen, the world’s most iconic rock band. Play their greatest hits at historic venues, create your own stage performances with unique animations and legendary outfits, and collect exclusive images from the official archives of Queen!

Answer 1

It's a video game in which you supposedly recreate the music of Queen.

I believe "hammer out" means that you tap on the screen (like a hammer taps) when playing the 'bass' part in the game. Likewise, "hold down" means that you hold your finger on the touch screen of your device to 'sustain' (hold the same note for an extended time) the vocal.

Sounds riveting.