Well I have to say that's one of the most complex installations I've ever attempted - and for arcade games!?
Well the phpBB Arcade 0.6.7 is kinda meant for RC1 of phpBB, but is documented to work for RC4.. with the minor issue of having to rename some of the database tables, recreate some of the php into every skin installed on the board, manually add the arcade links into each skin, then install each game individually.. not to mention changing permissions manually on a lot of the folders, plus guessing correctly to move the install php to an undocumented folder before trying to run it, oh man, there was even more crap too but I'm over going thru it again just to explain...
Aaanyway, there are now a stack of games being installed into that new link you will see up top - Arcade.. if you add any games as favourites by clicking the stars, they will also appear in a favourites manager in your user control panel. Only issue so far has been with the 'toxic' series of styles - they wont show the 'Arcade' link in the control bar.. so switch to another theme or...
bookmark this link.
Refresh the arcade regularly... I'm playing each game as I install them (all) - and there's a lot, so I'll probably be doing it for around a week.