I'd like to suggest a simple thing for testing purposes: a respawn button.
Other than that, it looks okay? The speed of the running animation (not the running speed itself) seems a little slower in comparison to the later MM games. This also brings me to a different suggestion: if you were able to take MM5's player movement info and replicate it, is it possible to allow testers and developers to actually see the differences between each NES game's physics, at least for testing and development purposes?
Also, please use a black/white tile and background combination with grid-like tiles, like that really old N64Mario MM engine, or something akin to MM8 Beta stages: it seems more appropiate for a physics test map.
A respawn button will definitely be something I'll put in later, when the engine is in alpha. I'll definitely add one in the future, though; thank you for the suggestion.
Also, this engine is not designed to replicate
Mega Man 9 or
10, so running speeds from those games are not going to be something I will deal with right now. (If I were to find those speeds, I would probably add them as comments in the code for horizontal movement if the developer would want those speeds; the same would apply for jumping.) Also, it is
indeed possible to add in the other speeds of vertical and horizontal movement from the other games for testing purposes; in fact, it would only require the changing of a few speed variables.
Also, I think a grid-like test tileset is a good idea. I'll create one and use it for the development of the engine.
Thank you for your feedback. It was helpful and fun to answer and address your concerns!