Well, it's not terrible, but it needs a LOT of improvements.
1. The music loop gets very annoying. There should be an option to mute the game's music.
2. On level 3, Dragonite was one of the catchable Pokemon and Dragonite isn't even a fire type.
3. There is no such thing as a magnet type Pokemon. Those Pokemon in level 6 are steel type Pokemon.
4. The shooting mechanic is sub par. It can't even successfully shoot a Pokeball that will catch a Pokemon the majority of the time.
5. Finally, it's Pokemon, not Pokemons. If you're really a fan, you should know that. Not to mention that you should know that there's no such thing as magnet type Pokemon.
Like I said, a lot of improvements need to be made. The idea is kind of interesting, but it was executed poorly.