We reported back in March that Sony was starting up a beta test program to see which Xperia phones could take on Android 4.0 (Ice Cream Sandwich). One of the hopes was that Sony’s flagship gaming phone, the Xperia Play, would see an upgrade to Ice Cream Sandwich. That appears to not be the case anymore.

In a post on the Sony Mobile blog, the company says that Ice Cream Sandwich wont be coming to Xperia Play after extensive testing on their end alongside the testing performed by those that participated in the beta test. It was found that the Xperia Play could not remain stable while running ICS and that it had a negative impact on the performance of games. Considering that the Xperia Play’s main focus is games with its d-pad controls and PlayStation style buttons, it’s a big deal if the phone can’t remain stable during gameplay.

That’s the only bad news, however, in a post full of good news. ICS will be hitting a wide range of other Xperia phones soon. The company announced that ICS would be hitting the Xperia S, Xperia P and Xperia U in tiers at the end of June. Three Xperia phones – Xperia Arc S, Xperia Ray and Xperia Neo V – were all updated with ICS last month. The other Xperia smartphones that Sony released in 2011 will receive ICS at some point during this year.

At this point, it seems that it’s only the Xperia Play that’s being left out of the ICS update. Sony probably made the right choice since an unstable OS would be disastrous for a mobile phone whose main purpose is to play games. The lack of ICS could also be pointing to a successor to the Xperia Play with advanced functionality. One of Sony’s most valuable assets is its PlayStation brand. Being able to market a smartphone that at least looks like a PlayStation device weighs heavily in Sony’s favor.

It appears that Sony is still allowing Xperia Play users to unlock their phone and install ICS to the device if they so wish. It should go without saying, but the software is unstable on the device. If you must have ICS on your Xperia Play device, you can still install it. Just know that it’s not Sony’s fault if your device breaks. You’ve been warned by a lengthy terms of service agreement.