There is not a time limitation on the $500 trial credit, the credit is available until completely used. There are resource limitations for 30 days for new accounts. Initial resource limits are 6 CPU, 10 GB memory, and 200 GB of storage.
After the first month it is possible to increase your resources.
If you can define your requirement CPU,Memory and Storage they can review your request.
Off course Google one of the best but Mining, Jingiling, Hitleap and high cpu usage cause suspend accounts.
But the that I personally using for Minirgate Mining tool with this service with great success. They allow high cpu usage.
PRICE: $15
There is no limitation on Instances for trial accounts . As long as you've got credit in your account you can create many VPS or Windows VPS.
There is not an expiration date placed on new trial accounts like GOOGLE, AMAZON AWS or AZURE.
SCREENSHOTS
