Your goal will be to come up with a novel mechanic for a grid-based puzzle, and a theme or hook that makes it readable and distinctive.
Remember you are always standing on the shoulders of giants (or just somewhat talented people born before you)
Explore the thinkygames database or itchio. Be prepare to present a game that provides an inspiration for your project.
But first:
Mobile is still the fastest growing sector of gaming – crucial state of the industry presentation here
Classic block pushing puzzles
Modern block pushing revival & puzzle script
https://itch.io/games/tag-puzzlescript
https://w.itch.io/herding-cats
https://pap4qlxxlevb.itch.io/stocking-filler
Beyond block pushing
Puzzle/simulation
Falling blocks
Match 3
See also Blue Jeweled – Match-3 parody
Roguelike (Broughlike)