Microsoft wants to deliver a new game to Xbox Live Arcade every week - and believes it's possible, too.

"I can say we've certainly put enough games into the pipeline and it's certainly our target," Xbox Live Arcade worldwide games portfolio manager Ross Erickson told gaming blog Joystiq this week.

"I'm glad [Xbox Live Arcade] Wednesdays have kicked off. Barring unforeseen development issues from the developers themselves - our issue was to fill the pipeline with a lot of titles on the upfront because of the inevitable schedule delays we'll have - we'll still have enough queued up in our certification process we'll always be able to have something coming out once a week."

Microsoft has previously said it aims to have 160 games available for Xbox 360 by Christmas, and a significant number of those are likely to appear on Xbox Live Arcade - as many as 30 by the end of autumn.

"We certainly have enough games in the pipeline - more than enough, in fact - to achieve that goal on a weekly basis," Erickson told Joystiq.

One thing Microsoft won't be doing - at least not immediately - is allowing developers to make games that occupy more than 50MB of hard disk or memory-card space. "That's pillar number one," according to Erickson.

The idea is to allow Xbox 360 owners who do not own hard disks to store downloaded Live Arcade games on memory units, which allow for 64MB of data.

However, with PlayStation 3 in particular likely to allow for much larger downloadable games, Microsoft runs the risk of losing out on bigger releases despite the impressive momentum Live Arcade has already built up.

Erickson admits that the company is already considering the possibilities of larger memory units, but there's no word on hard-disk-only Live Arcade games or other digitally distributed titles - although it's important to note that the latter, which Microsoft is certainly considering, would fall outside his remit.

"Certainly those memory units are not available yet. And when they become available we'll re-evaluate," he says of Live Arcade's position.

"We're constantly evaluating this not on just the size of the memory unit available, but in terms of what the quality bar is that we're asking for from developers."

"At this time and for the foreseeable future we're sticking to our position that 50MBs is what defines an Arcade title so that portability between system and system can work and so that those users who do not have a hard drive, don't think there's many of them, but for those that don't have a storage solution for getting their games onto their system."

The Xbox Live Arcade Wednesdays schedule consists of Frogger, Cloning Clyde and Galaga (the latter released worldwide today), along with Street Fighter II: Hyper Fighting (August 2) and Pac-Man (August 9).

Other games on the horizon include Texas Hold 'Em Poker, Sonic the Hedgehog from SEGA, Alien Hominid and Castle Crashers from The Behemoth and various others from the likes of Midway, Namco, Capcom and Microsoft's independent publishing and development partners.

Live Arcade games typically go on sale for 400 or 800 Microsoft points (GBP 3.40 / 6.80), although some - notably Bankshot Billiards - cost 1200 points (GBP 10.20). Free demo versions are available for all of them.