Is there a limit to the number of scheduled rulesets that can be run on cron every minute?

I am developing a game in Drupal, and will need to rely on having rules scheduled for a user when they perform certain actions. This scheduled rule will add a new role to the user and update their content profile, one hour after they click the link.

I imagine there could be up to a few hundred scheduled rules running when cron is run every minute (with a good amount of users playing).

Will I run into any problems? I am hosted on an Amazon EC2 Small instance, at the moment.