This is a good start to a game. The basic idea of not being in control of what kind of object you need to catch is a good take on the idea. A little bit of extra UI to help the player who is trying to split focus on the bottom of the screen to see the symbol and the falling objects might be to have the catcher change to be the same color as the symbols you are trying to catch. Add in a few more symbols over time to ramp up the challenge of the game. I also love that your color choices take into account colorblindness.