Performance on mobile devices

OK so I'm not a happy chappy today

We made a game which runs sweet in the browser. But when it comes to putting it on mobile devices it sucks the big one.

We have say up to 20 moving sprites as slow moving bullets, you can click on a sprite and draw a path and it follows it.

There's quite a lot of collision detection.

If I remove the background tile, foreground map graphics, and even remove all collision detection events, its better but still the more sprites on screen the lower the FPS and I'm not talking about hundreds of sprites, like 20-30

Even when we draw a line which basically creates an instance of a line sprite every 20 px the FPS drops massively, these are static low size sprites that arent doing anything and I dont get why the FPS should drop so slow

we have tested on iPhone and on win8 tablet simulator, its primarily designed for Win8 and it runs fine on a win 8 computer but the tablet simulator shows massive problems and I''m worried it will just get rejected simply for poor performance.

I would like to know what people's experiences have been with publishing to mobile devices, what limitations they met, how they got around them etc and any suggestions how i can stop the FPS dropping so much

As far as i know i'm not doing anything massively complicated here, slow moving sprites with collision detection, some of the spirtes have animations which i have slowed down and it helps, but even without the animations there's this drastic drop which seems out of proportion to the amount of stuff going on

please help!!!

Just one more point, if i publish as a standard html5 site, upload to a website and then run it via IE in the windows 8 tablet emulator then i dont have any problems at all!

Hi there, have you done a general forum search on optimising mobile performance? There are tons of articles, including official write ups from Tom and Ashley. First point - if you intend to release to iPhone or android use cocoon JS. It gives excellent performance.

If you're just looking at win8 the emu probably isn't going to be 100% accurate (ever tried the android emu?) I'd suggest talking to your local MS corporate branch for assistance - they could be pretty helpful. My local MS contact has been super helpful and has offered for me to go and test on their HP slates with win8 (no surface RTs unfortunately)

Also do a forum search for win8 and testing - there are a ton of posts. Iunkn is a local expert who has an excellent blog dedicated to c2/win8 mobile integration

Thanks for the reply, ill check his blog

i have followed all the optimisation guides and have alleviated most of the issue, but one main issue remains

When i click on the object and draw a line it creates an instace of a 10x2 sprite every 20 pixels, my objects then follow these lines

if i test in the browser i can create 2000 of these lines before the FPS drops, but in windows 8 i can draw only 50 and it drops (this is running on a local win 8 machine, not the tablet emulator) just seems like the export to win8 results in something that can only handle a tiny amount of sprites on screen at any one time, even if these sprites are small and not doing anything

Have you read performance tips? Creating hundreds of tiny objects is just about the least efficient thing you can possibly do, so it's not really surprising if that causes a slowdown on mobile...