I really don't see why so many people seem concerned about the number of scores kept in the database. I've had this installed since around the 2nd day it was released. I currently have 1,300 scores that are recorded and it takes up 133kb of space. My entire database takes up 260mb, so that would be around 0.0005% of the space.
As long as your asking for suggestions futureal, here's a couple of things I noticed... The places it checks the time & date of scores uses the date function instead of the vbdate function, so it doesn't show the correct time if it's been changed in the Admin CP.
None of the templates the arcade uses are called at the beginning of the script, so of course that adds unnecessary extra queries for each template.
I also noticed that you didn't use the free_result function after you were done with the queries, which of course isn't good for high traffic sites. Not that I think it's really affecting things too much, but it still wouldn't hurt.
As far as I remember those were the only suggestions I had for the script. Looking forward to the update and thank you for your hard work on an excellent script.