Terrible lagging of the PvZ2 ! Plese help me!

For the sake of the game, I bought a new device, but as it turned out, the problem is not in my old device, but in the game. I think the developers did not expect that someone will have enough patience to pass 1100 levels of Ancient Egypt Challenge with monstrous lags ...

I am running PvZ 2 on a tablet with the Intel Atom® x5-Z8350 Quad Core 1.92 GHz CPU (2016) and game still lags on Pyramid of Doom - Level 330. It is clearly a programming issue. From developer's point of view it could be that the game have an issue with zombie wave management i.e. it adds too many zombies too soon and then tries to process them even when zombies are invisible or processing is unnecessary. Maybe, for example, you have 50 zombies on the screen, and game tries to process image and sound of all 50 of them, when it could skip processing image of the zombie if it is hidden or skip sound processing of the zombie if this is 9th zombie and its sound won't make any difference. Also it seems like game has some sort of processing queue of events, will process all of it without optimisation, despite some of events becoming obsolete. It looks like new zombies are released when you kill some of them from the old wave (I can delay zombie wave by simply freezing them). I don't know how game is coded, but this behaviour could lead to leak, when multiple zombie waves are released if you kill just couple zombies from current wave, while there are a lot of zombies from the previous waves on the screen. Game speed will increase if I freeze all zombies with the powered Iceberg Letuce, because it will temporary suspend processing of zombies. Game still continues to lag terribly even if ALL zombies are killed, by using power up on multiple Ice-Pults, which means that game is processing something invisible very inefficiently. Anyway, this is speculation, but this is how lag issue looks from a developers point of view.