Maybe try something newer which supports WebAssembly?
The error message is as follows:
Sorry about that! Maybe try another ROM?
Cat Dash
You are a cat, you are hungry. Catch birds.
Enter the bushes to spawn your prey, sneak up on it while it is eating.
Moving uses energy.
Eating refills your energy.
The game ends if you run out of energy.
Controls:
Arrow Keys: move
Z: Meow
X: Dash
Enter: Start
Right Shift: Select
NES emulator by koute (not me).