What to do when my game is rejected by CrazyGames?

From the CrazyGames Developer FAQ, under the heading Uploading my games:

Can I submit a rejected game again?
Only if you have improved your game and it complies to our requirements.

One thing that is almost immediately obvious on your Itch.io implementation:

• There's no guidance on how to play & the player has about five seconds to figure out the controls before they lose.

That seems to be in conflict with the CrazyGame's quality guidelines under the heading "Is your game easy to play? Are the rules and objectives clear?"

Your current version shows a very brief splashscreen with your developer name / logo when the game is launched. As first step toward communicating the game controls to the user, I suggest following your logo screen with one or two screenshots that attempt to explain the controls to the user. This seems like a relatively low effort fix as you would be recycling something you've already developed to solve the problem.

I also experienced very erratic player movement in the game. On Itch.Io that you have the game marked as Status In development. It's understandable that a game is likely to have errors while it is in development. However, the guidelines on CrazyGames state that their expectation is that "errors don't hinder the experience". You should correct any obvious bugs before attempting to resubmit.

In general, when publishing to any platform, you should read and adhere to their guidelines.

As mentioned in the comments, ultimately CrazyGames determines which game are accepted and which are rejected & if you want to know the specifics regarding your situation, you need to ask them.

I just saw your game, and no offense, but it looks like it is subpar quality compared to the other apps on the site.

Off the top of my head, I can list several points that may be fundamentally wrong with your game causing rejection:

• Graphics: The characters have no animation, enemies have no animation, UI are simple colored shapes.
• Feedback: Your game doesn't have any feedback or particle effects on impact when you kill a zombie.
• Audio: Only simple music, no sound effects for shooting, impact, or zombies.
• Gameplay: It is just too simple. No progression, no rewards, no store, only a score kept for shooting zombies.
• Game Over: After the player dies, there is no way to restart the game. It just stays frozen at that screen. This alone would get your app rejected on any platform.

These are just the basic things that are wrong with the game in my opinion. In short, the project looks like a new high school programming project. All the apps on CrazyGames are production-ready, fully-fleshed out games. I suggest you maybe get some experience doing game jams, getting feedback from other game devs, and get better at making games in general. Hope you can improve and get better at game dev and eventually get a good project published!