SE gave players a cool cap and a chair in DQBII depending on how far through DQBI players made it, just as another example. I wouldn’t necessarily call either of these “failed” games but there is certainly precedent for getting rewards in one game for having played a previous iteration. Herme’s Shoes (for playing FFXI) and Asuran Armguards (for playing FFXIII) are examples of other time-gated special items granted to players who played other SE games at the time (technically Asuran Armguards can still be obtained but only if you have a new first-print copy of FFXIII, and even then you have to work with SE’s support team since the codes don’t work any more, and depending on who you talk to there they may deny it so I still consider it a time-gated item).