5 Month Old Not Very Interested In Toys?

20-30 minutes is a long time for such a little guy! I don't think you have anything to worry about. Most kids like toys that aren't even really "toys" Give him some pots and pans (if he can sit up unassisted) or sit next to him and let him bang on them. My niece used to love that. Or our cell phones! Pretty much anything that wasn't a toy she got her hands on!