The /d/ in 'mind' and 'sound' are probably less aspirated than when they follow a vowel, because in /nd/ the tongue is already on the alveolar ridge for /n/, and /d/ is only produced in releasing.
The 'o' in 'God' is longer than the 'o' in, say 'mod' or 'good', and /d/ might not sound as strong.
If the word after 'good', etc. starts with an unvoiced letter, as in 'good song!" for example, the /d/ might also be less voiced, and sound closer to a /t/.
German speakers tend to pronounce terminal /d/ as /t/, because that's what happens in their language.
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