What much can I really say? This style has been done numerous times. The Creeps play infectious, upbeat punk, born of the Ramones and sculpted by Screeching Weasel. Somewhere in the genre's history, bands like the Groovie Ghoulies shifted the concept from straightforward silliness towards specific niches. The Creeps carry that torch onward.
On These Walls The Creeps play their music well, with the harmonies running together smoothly at appropriate times, and there's enough variation between the five songs here that it doesn't sound like the needle is stuck, despite the lone beat that permeates the record. When things start getting samey, singer Skottie Lobotomy throws in a Glenn Danzig style "whoa-oh" to break it up. I'm amazed it still works after all these years, but it gets me singing along every time I hear it. The band can set a good pogo tempo and transition into melody smoothly and that's their strength. However, it's strictly genre music and there is a wealth of current-running bands with a similar sound. There's probably one in your town, wherever that may be.
In short, The Creeps do the pop-punk thing pretty well. If you're a fan of the genre and its recent crop of bands, you should definitely check them out. But, if you only have a passing interest you may as well move on. You already know what this band sounds like.