Let's look at the phrase: "Bonus! 4 games on the flip side".
1. The word "Bonus!" is a short, excited way to say there is something extra or special.
2. The number "4" means there are four games.
3. "on the flip side" means on the other side or the back side of something.
Putting it all together, the phrase tells us that there are 4 extra games located on the back. It's a short and clear way to grab attention.
In terms of grammar, the sentence is okay as a catchy phrase or headline. However, for writing in full sentences, we might say: "Bonus: There are 4 games on the flip side."
Also, remember to write the number "4" as a word "four" in formal writing, especially for young students.
So, the phrase is correct as a headline or label, but in full sentences, it should be a bit longer and clearer.