The form is not submitted when you click on Submit and no errors are displayed using globalErrors.

There may be a situation where a particular required field is missing or there is a typo in the name of the field. It will not be shown in globalErrors but if you attempt to display the error for an individual field, error.required will show up for the missing field.

Do we need to use Twirl templates for the application's views?

No, Play does not force developers to use Twirl templates for the views. They are free to design the views in whichever way they find easy or comfortable. For example, this can be done by using Handlebars, Google Closure templates, and so on.

Does this affect the performance of the application in any way?

No, unless there are no performance flaws in your view definitions, plugging it in a Play application will not affect the performance. There are projects that use the Play server for their...