I am getting following popup while previewing my game on mobile devices. This popup is not coming when i am viewing it on PC. Anyone have any clue why this is happening ?

See scirra.com/tutorials/67/delta-time-and-framerate-independence Delta-time and framerate independence. All the built-in behaviors already use dt, you don't need to use it with them.

Yes but there is a line stating that Physics is an exception and it does not use dt. Is this applied to CarPhysics too ??

Ashley: Can you help me in this ? I want to add dt in the car physics acceleration. Without this, my car is running fast in computer and slow in mobile. But there is no option in Car Acceleration action to multiply it with dt.

Or is there any way round that the car speed will be fps independent.

It's quite important to ensure that things behave at the same speed across devices. <img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":)" title="Smile" />

https://www.scirra.com/tutorials/67/del ... dependence

Ok I read it. I haven't used it in my game. I am using Car Physics behavior. How can I relate car acceleration with it ? There is no option.

jakobdam: ahem.. What is 'Dt' ??

jakobdam: Well.. Just a quick question. I think I got the problem. The problem is not performance of game, but the car behavior. The game is running at smooth framerate, but my car is just driving really slow like a turtle. What can be causing this ??

trovao1990: Thanks.. Now its my time to pack bags to Himalayas.. On serious note, I think I should take another look on my gadgets..

jakobdam: What seriously ?? then why it lags in my iPad 4 ?? Can you please do me a favor. Can you please check it on mobile device, like any normal android device ? If it still don't lag, I will throw away all my devices and will take retirement and go to Himalayas. (just kidding )

Ashley: If you have seen my game, there are many objects (almost all are static). I was just thinking, do I need to add physics behavior to all objects ? By only adding collider and checking collision with car object (in my game), will this increase performance ?

jakobdam: I have uploaded my project on a server. Here's the link

goo.gl/lomzR5

you can replace rotate by rotate animation

In my game, there is no rotating objects. In fact Only player car is moving, by car physics behavior. Every other objests are static

jakobdam: Thanx for this detailed analysis. Took hell of a time to understand every point.

Well, i will start from point to point.

-I am using sprite font, but they are not used too much (as you can see in screenshot), only once, that too, is not moving

• Here explain me one thing, if I switch layouts, will the sprites from previous layout is destroyed automatically ??or do I need to destroy it at start layout event ?
• As you have guessed, all bg and objects are static, only car is moving. (in some cases AI cars moving), so nothing problematic here.
• I will check it and tell. Also I am trying some more things. if it still not work, i will try to produce a playable link for you to check. I dont want to go back on this game now as it is almost complete

Yes.. Other screens appears smoothly. Just in case of levels, like this, (there are 10 levels in all). the game lags in this only.

But the case is, the game is significantly lagging in mobile devices.