Street Fighter x Tekken & Super Street Fighter IV: Arcade Edition, PC – £9.07
Street Fighter x Tekken & Super Street Fighter IV: Arcade Edition, PC – £9.07
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Street Fighter x Tekken registers on Steam.

Irritatingly only Street Fighter x Tekken registers on steam; the other requires GFWL. 🙁
They both require GFWL anyway, even if you have them on Steam.