After several tries and about 15 Minutes of waiting, I still wasn't able to play a single game of Transformice due to server issues. I don't know how good it is, but it seems like I never going to find out, so 1/5.
Not bad at all. It is like Castle Crashers meets The Legend of Zelda. Graphic fitted to the theme(+2), music was not bad but damn repetitive - a theme more would not have hurt(+1), Gameplay was great fun, especially the RPG Elements(+2), Balance was an issue. The beginning was to hard, but later the standard fiends were no challange at all, while the bosses were just to damn hard(-1).
Overall: 4/5
Impressive. By using basic structures of human psychology you create a addictive yet pointless game. Use this idea to achieve more for yourself. Start a own site like good ole O-Game or similar.
 "Depict1"){kind=icon}
 "The Fog Fall 3"){kind=icon}
 "Transformice"){kind=icon}
 "Daymare Town 3"){kind=icon}
 "Chibi Knight"){kind=icon}
 "Anti-Idle: The Game"){kind=icon}
 "Dragon Age: Journeys"){kind=icon}
 "Canabalt"){kind=icon}