Kiyoshi, please don't underestimate the use of Paint for pixel arts. I can tell you two or three Large communities where all the senior artists started his careers using Paint.
So, if the C2 is for everyone, I believe many of Our beginners will use paint for pixelart, a software free, come with the Windows and on MAC have a similar one too. =]
Trust, nobody need Corel or anything else than Paint to make nice pixelarts, but Paint still limited when talking about transparent backgrounds and semi transparent colors.
Indie Game Maker (also called as IGM) have a feature where it detect any mix of that pink, used as a key color, to detect semi transparent colors, you can setup how much sensibility deep IGM will use, so, that tool don't obligate you do use any thirty part software than IGM and a brand new Windows or MAC. ^^