C++ is the canonical example of a language that combines low-level and high-level features1. It doesn't simulate anything, it provides native support for almost every high-level construct you'll usually find in a common high-level language and almost every low-level construct you'll find in C.
But of course the terms are highly relative, there was a point in time (not that long ago2) where C was considered a very high level language. And there are quite a few other languages that offer considerable low-level functionalities while still commonly regarded as high-level, and vice versa, the lines are kind of fuzzy.
As for the syntax, that's something that naturally affected by the language's level of abstraction. Low-level generally means:
In computer science, a low-level programming language is a programming language that provides little or no abstraction from a computer's instruction set architecture. Generally this refers to either machine code or assembly language. The word "low" refers to the small or nonexistent amount of abstraction between the language and machine language; because of this, low-level languages are sometimes described as being "close to the hardware."
So naturally a low-level language adopts a syntax that's closer to machine code, which is inherently non human friendly. Quite a few languages, like C++, have adopted a wide variety of syntactic sugar, as a mechanism to make things easier to read or to express. But syntactic sugar is something that almost every high level language has opted for, C++'s sugar alone doesn't make it a low-level language.
As for the complexity of a low & high-level language, it's also natural: It's a tool with multiple goals, every single goal adds to its complexity. That's unavoidable regardless of the goal. High-level languages are not "better" than low-level one, they are just more concentrated on one goal. Languages that are designed with ease of use as a primary goal tend to be high-level, but that's only important if the necessary trade-offs to achieve the goal don't affect your applications.
Low or high level doesn't really matter, languages are primarily tools. You should choose the one that best fits whatever you're building in combination with what skills you have. Most popular languages are multi-purpose and Turing complete, in theory they are valid choices for building almost anything. There are no absolutes, of course, you may win in some areas if you opt for a high-level language and in others if you opt for a lower-level one, even within the same application.
Most large scale applications mix and match, following the "right tool for the job" mentality, and that's a more efficient approach, imho, than trying to have your cake and eat it too.
1 But please note that there isn't a definitive answer on what's considered a strictly high-level feature and what a low-level one.
2 In human years, in software years it was long ago...