All the IB mobile i5s I know of are 2C4T. In the case of a notebook, the lower TDP is probably better to have than more cores, anyway.
i5+ to play a flash game.. that is sooo bad. If old Steve was right about one thing, it was about flash. (ok one of the MANY things he was right about).
Not to play it, but if you're going to keep the computer for several years (he's not exactly looking to replace something from the last couple years

), more performance now can significantly extend the usable lifespan. An AMD A-series would do just fine, too, but overall, the Ivy Bridge Core CPUs tend to be better values, if you plan to keep it until it's just too slow, and tend to be your options in overall higher quality notebooks.
He was right about Flash, but it was in a
very different context*. This performance issue would occur with or without Flash.
Hardware performance v. programmer productivity has been an ongoing thing for decades (definitely since the early 1970s). Dynamically typed systems with automatic memory management exponentially improve programmer productivity, at the cost of the end result's performance. Flash is largely powered by ActionScript, an ECMA dialect (basically, Javascript). It supports object-oriented programming using dynamic prototyped objects, very loose dynamic typing (5+"1" might equal 51, FI, but I'm not 100% sure that AS3 is that loose), and automatic memory management. Even with a VM that natively compiles, it won't be able to touch the speed of Java or C#, much less C++. Also, with many different graphics operations to be done, it will be stuck with tons of VM/interpreter overhead, not unlike the API call overhead game devs complained about in older DX versions.
It's a trade-off. Much higher programmer productivity could very well be the difference between being able to afford to make and support the game in question, and not being able to do so. The necessary dev time, testing time, and time spent tracking down and fixing bugs, for a language offering more control, like C++, might not be affordable, especially when the business is fairly small.
* This is obviously searched for a great deal, because it was one of the first few hits. I wasn't even sure that such a page existed, but figured I'd Google for it anyway.