This app was mentioned in 10 comments, with an average of 7.00 upvotes
You are probably thinking of the mobile app, Forge of Empires. This is a screenshot of Age of Empires II which originally came out in '99 and is an amazing game.
I have zero experience marketing but wanted to share my thoughts as a first impression seeing your trailer. It's going to be negative but maybe you can change things for the better.
The trailer shows nothing about the game. Maybe it does, I have yet to read the description. Put it this way, if someone said watch this video and gave mo context I wouldn't even know it's for a game until the end when saw the on google/apple. I sure as heck have ZERO idea on what type of game this is or how it's played. How are you going to effectively market a game without showing, well, the game.
I really dislike cg type trailers with mobile games since they never look like the real game but if you want an example of it done right, Forge of Empires - google play. I can tell right off it's some sort of building game. It doesn't have an "available in ios" on an android store video! Your trailer looks more like an intro to some animated series with emoji/pac man type characters. I would completely redo the trailer and make a new one about our game. I would keep it's graphics closer to the games graphics because after seeing the trailer, then the screenshots right next to it, I realize the video doesn't represent the game in content or looks. That makes me not want to try it.
Wish you luck on turning things around.
I am really curious what it might be since im guessing it is not Forge of Empire
This game looks promising... just found it! https://play.google.com/store/apps/details?id=com.innogames.foeandroid