Can we do that or is it MBP a better choice?
The MBP would be a better choice for most games due to having a active cooling.
If you plan on doing light gaming with the MBA, this would probably be fine. I have seen videos of people playing WoW on the M1 MBA.
The issues with gaming on the AS MBA is the longer you game, the greater chance of thermal throttling. So, pretty decent performance initially, but as the GPU heats up, the performance could decrease.
Of course, all this depends on the game and graphic settings.
I don't think Roblox is a very demanding game, so you could probably play without issue.
All that said, any AS Mac with a fan will mostly outperform any passive cooling Mac when it comes to gaming, but if gaming is not a priority, the MBA might be good enough for you.