If Crayon Physics was a pre-installed bloatware application, then you must root to delete it. Ice Cream Sandwich lets you "freeze" the app though that may not be what you are looking for.
If you side-loaded the application, then I have seen times when an application won't show under the Market application because it doesn't have a signature the Market recognizes; that is, you didn't get it from the Market.
If you installed the application, go to Settings - Applications - Manage Applications. Under the 'Downloaded' tab, you should be able to find it. Again, if it was pre-installed, then you didn't 'download' it, so it won't show up here but you should see it here even if you side-loaded it.