I have experienced many games and when i open them up, i quickly move to home screen within 15-20 sec but this game loads very slow and it also restart even if i close for a little while. Plz make it load faster plz a humble request Devs 
Dont take it to personal or I have a solid reply for u but i have to quite here in open chat !!
Devs might have to get naughty with the code to make the game faster you know…
My Neo Monsters app takes exactly 2 minutes to load in, which is ages! I use an android Huawei P9 lite. I also see huge delays going between some screens: team select, changing sort mode to “training” and turning on/off secret skills.
However, I see how on my brother’s iPhone (newest?) that all load times are super fast. Therefore this is either an android problem or due to the limitations of each respective phone. I do not have issues with the app closing if I leave it running in the background for long periods of time unless I open lots of RAM-taxing apps.
My conclusion is that this is probably just an issue with your phone @Abrar and how it can’t load things quickly then when you leave the app running in the background while opening other apps your phone chooses to close it because there is only so much RAM available. I suggest you make sure you don’t have your phone running lots of processes at once.
Don’t take my word for it completely, I might be 100% wrong, but that’s my advice 
Galaxy S9. 29 seconds to “start game” and 40 seconds to interaction with home screen. Both times from tapping the NM icon.
Iphone 8 here and 16 seconds to reach start game button and 25 to interact with the home screen
I am also annoyed by it taking so long. Using an Huawei Mate 10 Pro and it takes about 45 seconds until the start button and almost a minute to actually do stuff.
Although it is a quite potent phone, I also experience lags ingame while switching menus frequently (not server or connection related). Can’t remember any game with such a long period to launch. Considering that neo monster doesn’t even challenge the hardware, this is a bad result and not understandable from my side.
iOS seems to be significantly faster than Android though.
31 sec from from starting a game to its game homescreen - Asus Zenfone 5Z