As big as my mind is, even I either make far-fetched connections or can’t find one at all. If an overwhelming amount say the connection is fine, I’ll take it down. P.S. your goal is to get to Mario.
Wheelman (said it has several car models from GTA)
Rainbow 6: Vegas
Omikron or Farehnheit (both are connected, several games have Asteroth, and I said Omikron and DmC are connected because of demons.
Time Gal (said it was to Mortal Kombat, forgot how)
Project Gotham Racing (connected it with the feraris in GTA
Titanfall (connected to Dead Space)
Knack (connected to Titanfall)
I am Alive
Metro: Last Light
Beneath a Steel Sky
S.T.A.L.K.E.R. Shadow of Chernobyl