That's quite an interesting idea there, taking the classic snake formula, and combining it with some exploration and key collection mechanics.
On the surface level, the game looks like the classic snake: you navigate by constantly moving in one direction, alternate directions by pressing the directional keys, and die if you hit yourself or a wall. Unlike the original Snake game, however, instead of your goal being to collect pellets to make the snake grow, you need to reach the end of every level.
In order to reach the end, you need to explore the levels to find keys and open doors. It's a pretty neat concept, and it also allows for some sweet optional secret rooms, which I found quite neat.
This concept has limitations, though. For instance, unless I know exactly what is contained in a certain room, I may move the snake in such a way that I get blocked by my own body from the place I need to go to next. The fact that this game has a lives system (why? There's a reason game designers have abandoned that in recent years) only makes this even more frustrating.
Also, the controls are a tad irresponsive, especially when I need to maneuver quickly to avoid hitting a wall or myself. Other than that, though, this is a neat experience.