This sort of came up in another thread recently. It wasn't quite the same thing since it was to do with scrolling, but it's kind of related. Basically if you use letterbox integer scale, point sampling, low-quality fullscreen mode etc. for pixellated display, then scroll to an object moving at something like 40 pixels per second, you get an irregular scroll pattern. 40 doesn't divide neatly in to 60 (the most common display refresh rate) so you get an irregular on - off - off - on - off - on - off style pattern which looks bad (the human eye much prefers regular updates). And the cause of that is maths, not any particular aspect of Construct 2. Then it gets more complicated when you consider different display rates: it will look OK on a 120Hz gaming display, because 40 divides in to 120 (exactly one pixel every three frames).
One of the issues is pixel rounding rounds the display position but not the actual stored position, which is also why you can get uneven stair-step movements as the X and Y axes update at different times. You can probably resolve that just by making sure the object starts on the same pixel offset on both axes. Then you have to avoid features that adjust the position smoothly as well. Then you also lose the benefits of framerate-independent games: it could well run at double-speed on a 120Hz gaming display.
Construct 2 is a modern game engine so everything is done by floats with delta-time, which is often useful for smooth, accurate and consistent movement. However older games on much more primitive hardware would have manually adjusted positions as integers on a tick-by-tick basis. You can also do that with events, but it means not using the built-in behaviors. Also I am fairly sure modern displays make this more apparent than it was in the heydey of older consoles - something like the NES would have been running at a tiny 256 x 240, likely on a small CRT display, which were often slightly fuzzy making pixel boundaries less obvious. Run the same game on a 1080p display with perfectly crisp pixels, making each pixel a large clear crisp square, and suddenly you notice things you might not have noticed before.