The Player recognizes all the time signatures provided in the editor.
This is how they are interpreted -

4/4, 3/4 and 2/4 simply play as written in all styles
2/2 plays as 4/4
3/2 plays as 3/4 + 3/4
5/4 plays as 3/4 + 2/4
6/4 plays as 3/4 + 3/4
7/4 plays as 4/4 + 3/4
3/8, 5/8
6/8 plays as 2/4 so a triplet based style like Afro 12/8 is recommended for this time signature
7/8 plays as 2/4 + 3/8 and does not work with triplet based styles like Swing and Afro 12/8
9/8 plays as 3/4 so a triplet based style like Afro 12/8 is recommended for this time signature
12/8 plays as 4/4 so a triplet based style like Afro 12/8 is recommended for this time signature
Time signatures can change within a song, for example, for each section and as often as each measure.  This allows you to create sophisticated compound time signatures.
Here’s an example of 9/4:
Note: 4/4 is the default time signature if none is chosen at the beginning of a song.