Requirements:
Firefox
Cheat Engine 5.6
Flash Player 10

Steps:
1.Enter Happy Pets
2.Open Cheat Engine 5.6 (hex,Array of Bytes,ASROM)
3.Laser your pet and you will gain coins and exp(after click the LASER, click it to your pet)
4.Scan 85C00F848B0000008B48088B49548945
5.2 addresses may return. Right click the bottom address and Disassemble
memory region
6.You will see the code test eax, eax
7.Change it to test eax,ecx
8.Now click the laser and click it to your pet and now do not move your mouse because it will freeze your exp and coins, now you will see your coins and exp non-stop increasing, after you level your exp and coins are stop(Per one click per one level and your coins increased)
9.You can now move your mouse whether you publish or skip, once you are satisfied
10.Shift some furniture to auto save your game.
Have fun!