Okay, so just a heads up:
1. Your stamp message has nothing to do with my Critique
2. I am brutally honest and will not kiss your butt.
Now. To start this off I'm going to talk about font. Comic sans is a really good way to make people think you have no idea what you're doing. In recent years it's become something of a joke among visual artists, specifically people studying Graphic Design or Typography. Believe it or not; your choice in font says a lot about you and can either make or break your statement, and the next obvious step isn't to pick another core font but rather find a font that you think flows best with your message. You can find a metric ton of free fonts here www.dafont.com/
probably one of our greatest resources against boring type faces. You also don't need to limit yourself to one font. You can have as many fonts as you want, just be prepared to work harder, not exactly the end of the world but you'd be surprised about how some people take that.
Now onto the design itself, this one in particular is not completely illegible, but the text kind of sinks into the background, which really isn't a good thing. In almost every case the best way to make text really POP regardless of the colors is to add a stroke to it. I see you're a gimp user so this is a great resource www.gimpology.com/submission/v…
Finally, and this is for your overall stamp work, you NEED to align the text to the center, it makes the text flow a lot better, looks professional, and over all makes it look cleaner. Here's a tutorial for gimp users gimptips.com/articles/aligning…
That's about it, please take all of this into consideration, as I went the extra mile to bring you resources, something I wouldn't do if I was just trying to bash you.