Thanks for your feedback. I am a kid in Year 4 (as of 2019), and this is the second app I have created and uploaded. I will change the emojis with pictures. Tell me if you have any further suggestions.
Great, then i would suggest you the following.
1)Try some game engiene like unity or real engiene. It might be difficult at the start but once you get used to it, everything will be worth it.
2)Try to replace your ui with some photoshoped designs or simple pics in google(royalty free)
3)Try to build a community either in youtube, twitter or discord. This will greatly help you once you start making great games. And will help you to achieve the same
4)Get advice for colors and Gamplay from as many people as possible before publishing.