My feedback for Three Lines:
What your game does well:
Your game has a unique mechanic that involves color matching and switching characters.
The audio fits the tone of the army of zombies hurling toward the characters.
What your game doesn't do well:
Despite the tutorial, your game has controls that ask a number of things of its players. If there is a zombie of color X and my hero of color X is in a different lane, I have to switch their spots once/twice, then I have to shoot, and if I confused A/D with Q/E i have to retrace my steps and get them in the lane they need to be in.
Your interpretation of the them is moving in and out of characters, but by that definition any game that requires the player to switch their control between multiple characters can be considered an interpretation of this theme. I believe there's more you can do with this.
Areas of Opportunity:
I could just be bad at playing the game. But I believe there's an opportunity to make the controls less confusing. What I'm referring to is the distinction between the actions of switching between lanes and switching the characters in two lanes.
The players eyes are on the zombies trying to identify the colors for 90% of the gameplay. I recommend adding more visual and audio feedback to notify the player of whether they switched the lanes or the characters in both.
I hope this feedback helps!