I tried to build a basic examples to android. Even the most basic one with only 1 cube in it was 42 mb in size. And fps was low as well on my samsung m51 smartphone…
Is there a way to improve the performance and the size of the apk?
For mobile devices, 3D graphics need to be optimized carefully. For instance, all Flax Samples run at ~45-55 FPS on OnePlus 7. Did you test Release build?
For 2D rendering per is way better as 3D uses more resources.
Also, we use Deferred Renderer and on mobile, with over 2K res screens it tends to slow down since we didn’t implement fully tiled render passes yet on Vulkan.
Regarding the apk size I think we need to add support for stripping Mono libs that are unused by the game code and add options for compile optimization for-size (as we setup for-performance options).
I tested a release build. samsung m51. I don’t know how to display fps yet, but I think it was less then 25 fps
Ah probably shadows, screen-space reflections, ambient occlusion, and other high-quality effects were enabled so it’s a quite good result 
If you didn’t tweak any graphics settings then the renderer was doing PC-quality.
Take a look at Flax Samples:
Those projects contain ready-to use Debug UI (with fps and perf timers) + virtual joysticks for camera movement on a phone.
tried a basic template. release buld - 20 fps, development build - 9 fps
i enabled the “Mobile” and “DebugUI” actors. Also, I tried to switch off all the effects in Mobile Graphics Quality. Then built it with development mode, and it gave me 9 fps, then I built the same thing as release, but still get 9 fps. weird.
Would be great to have a sample optimized for mobile because I am not yet familiar with an engine and don’t know what am I doing
Yeah, we have some work to do for 3D on mobile but I’m sure we will get there. Especially, that we plan to add iOS support during the upcoming months.
I’ve created a tracking ticket on a roadmap to keep this in mind: https://trello.com/c/CeD5O0WW/325-mobile-performance