Is video game testing a job to do with computers

It depends on what types of games you are testing.

You may have to play games on computers, simulate operating systems on computers or enter reports and bugs on computers.

I would say 90% of the times, a computer will be involved.

1) Using computers with PC games is obvious.

2) some mobile and proprietary systems are developed on the PC.
To testing, you get a PC and run this proprietary system on the PC.
At the end of the project you may port it to the final device.

3) most times, you have a PC for entering bug reports, emailing, tracking Test cases completed, etc.

I have been in Video Game testing for 12+ years. Run a professional game testing company called GameInstict.com and have developed training for Video game testing that is offered at PowerUpGames.com