I feel differently than Kim Mak about it; I am not fond of the mixture of pencil with the "happy" letters added in digitally. Personally I just feel that it makes it look like an altered doodle (I don't mean for that to sound rude). I think I would like the shirt a lot better if it was either all pencil (you could use red colored pencil for the letters if you wanted), or all digitally done. I really like your concept, just not the mixture of doodle and digital.
About my design
Filled with A&W
If you got ice cream
Make it a double scoop
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