Online photo editor review

Reviewing a online photo editor is much harder for me than an office suite because, despite how much I like to say I'm a bit of a geek, I've never used a real photo editing program (no, MS paint does not count).  The extent to which I've ever edited a photo is to reduce its size and file size for use as an avatar, most recently for my picture on the e-learn site for this class, actually.  Thus, my choice of which editor to review came down to which name I like the most, and that was Sumo Paint.
Being not at all familiar with photo editing software, it seemed pretty easy to use. One click from the home page and I had the program running, and very shortly thereafter I had a picture up to edit.  (It took me a bit longer because I have pretty much zero pictures on the laptop from which I do most of my classwork, so I had to go download one from Facebook.)  All the tools that I could imagine ever needing were open in front of me right away.  The only thing I had to look for was the picture re-size tool, but it was right where I expected it to be in the "image" drop down menu.  It actually felt a bit like Microsoft Paint, which I find as a plus for people who might be resistant to using new software and enjoy familiarity.  I was easily able to find tools to add text or drawings, and to choose and alter the color of those things.
I'm not sure that Sumo Paint has some of the more powerful tools that serious photo editors might want.  To be honest with you I don't know exactly what those are, but the fact that I had a good idea what pretty much everything I saw could do tells me that it wasn't very serious stuff.  It does appear that there is a paid upgrade, which I imagine is the full-featured version of the software. Since the point of this review is to analyze it as a free alternative, I'll leave that out.
In all, I think that Sumo Paint could fill any needs I could ever think of for my own photo editing, and also any I could think of for a colleague or student, with the exception of possibly some more involved photography or art teachers/students who need more powerful software.