tryhard

Short definition from Wiktionary

Noun

1. 1
   A person usually of little talent who tries hard to succeed, especially through imitation, usually to gain fame or popularity.
2. 2
   A person who is perceived as putting too much effort into something recreational, such as a game.

Adjective

1. 1
   Done to excess, to an embarrassing degree.

Verb

1. 1
   To put perhaps too much effort into a recreational activity, typically a game.