Creeping state of some old Mammillarias is normal. Mother plant is too high so is falling and offshoots are growing upright.
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But this one seems to me not to be so old and like it was not given enough sun or was given too much water in past.
The one that grew on full sun have 'mamilas' closer to each other and stronger spines. Maybe in winter you should keep it on full sun too, if it is possible.
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But now all you can do is tie it to some stick. You can't change past conditions. It is healthy and flowering, and with more sun it will get stronger spines and a bit more compact body.
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It seems to me like Mammillaria backebergiana, the one that is hard to keep compact. This one really needs to be watered rare and can stand completely full day of sun. It is very resistant pant. Only frost is that it doesn't like.