You should be able to boost the resolution too by editing the below to this. This replaces the resolution of the 1280x960 resolution to 2880x2160.
Attachment:
virtuatennis.png [ 107.45 KiB | Viewed 2115 times ]
When changing the aspect ratio, you only need to change the final one found in the VIRTUAL_TENNIS_PC.exe. No need to change all 6. Well that's I found in my testing.