Possible, maybe, with the use of special filesystem drivers.
Recommended, no – Windows does not natively understand Linux filesystems, so any windows based partitioner simply won’t work the way you might expect.
My preference would be to install gparted from the official Manjaro repo, and use that. By contrast, Gparted understands M$ filesystems, as well as Linux filesystems, so it’s an obvious choice.
Keep in mind that extending the / (root) partition is potentially risky – if it must be extended, only extend from the end of the partition, not the beginning. You might be better served creating a separate partition rather than keeping everything on /.
With respect games stored on an NTFS filesystem: NTFS simply doesn’t support Linux permissions, so that might always be a problem at some point. Plus there’s the inconvenience of Windows chkdsk.exe being the only reliable way the repair an NTFS filesystem when needed.
ext4 is generally preferred – of course the caveat is that you lose the ability to share a game folder between Windows and Linux, which many blindly assume is a good thing.
exfat is sometimes used for sharing between Windows and Linux – the downsides are, like ntfs it doesn’t support Linux permissions, and it’s not a particularly robust filesystem. In fact, the only thing it has going for it is that it generally gives very little trouble.
If you find a half hour to spare, the following Primer might be illuminating.:
Regards.