Hi Pragun Agarwal Just read your team's idea and think it's great. This challenge resonates with me a lot. as gratitude can feed our engagement in the work we do. A couple of ideas:
1) You guys can also make hard copies cards with the same theme and looks so that the employees have an opportunity to deliver it in person and have a face-to-face conversation, which very often allows us to learn more about our colleagues.
2) Having a board game or an online game could be the next phase of your implementation plan. It's an additional way to apply/use the same concept.
Good luck with your project!
Cristina