Tom & 
Ashley
I have noticed the arcade server gets a lot of traffic and will at times slow to a halt when uploading or viewing a game and we get 404 and other errors quite frequently which is frustrating to players and designers.
I have notified Tom and he has said he is looking in to the issue and they are aware that the server is probably overloaded and needs an update and server updates are expensive.
I would like to suggest some ways to extend the use of the present server and for Scirra to make additional revenue from the arcade to put towards server updates and maintenance:
1- There are probably many games that never get played after uploaded taking up space. I suggest any games not played after 30 days you notify the game owner that the game will be deleted and then delete. They can update and reupload if it is that important.
2- Limit new game designers without experience points to 5 game uploads. They can replace a game that is not getting played. Limit all game designers to 10 uploads and maybe offer a price service for more than 10 game uploads.
3- Allow paid advertising in the side bars of games. Games advertisements must be created with C2. Allow other paid advertisements for outside games at your discretion.
That would reduce the space used on the server increasing reliability and the extra revenue would allow Scirra to buy servers and do maintenance that keeps the arcade working and popular.
Just my opinion and if there are other suggestions put them in the comments.