Waiting for your next game!
This is a well-made game if you ask me. I really took notice that you use the arrow keys to navigate through the UI. This is a great plus factor since it will leave the player’s burden of switching hands off the mouse and keyboard. As a matter of fact, since the game only uses four-direction and one action key, I might suggest that you could add a mouse-control feature (e.g. the character follows the mouse pointer and left-click as action button).
Now for the categories.
Graphic is 8. You used some of 16-bit games sprites, which are already good, and you combine them in a decent not-too-goofy design.
Style is 8 as well. Great game overall. Just for future recommendation, maybe you could add dynamic camera zoom, like the ones in most SNK fighting games, where the camera zooms to the action when the players are close to each other.
Sound is 7. You use memorable stage themes and a remixed version of the boss theme for the title if I’m not mistaken. Good choice of music although some of the sound loops are not continuous (e.g. the emerald hill stage).
Violence is 5. Well, you don’t expect much violence here, do you? It’s good enough.
Interactivity is 9. Great UI design, great controls, like the extras, which leads to a great game. 9 means near perfect although I like to see you go beyond my expectation on your next game.
Humor is 7. I like Sonic characters, especially the ones on 16-bit platforms. Nevertheless, I chose Mario as my favorite for this game haha.
Overall is 8. Great game! Your work is highly noticed. Keep it up.
To be honest, I didn’t take much time playing this game completely. I only had a minute or two to get straight into the game. However, that first impression really urges me to write this review, hope it helps you to improve more on your next game.
Suggestions:
- Add mouse controls
- Add dynamic zoom
- Fix the sound-loops
- Add winning pose for the characters, it adds the fun 
Well that’s all from me.
Best regards,
Jannata