I've officially been poking around in this game's files for too long but I have finally found not only how to get it in fullscreen but also how to get the second achievement that seems to be broken. 

They're all separate games but on a technical level the files are interchangeable. So... that's what I did. 

Eu acredito que você clicou aqui neste guia porque estava preso na segunda fase do ICE TEMPLE ou nas fases do WIND TEMPLE porque o fireboy e a watergirl está andando ou pulando muito lento em comparação com o tempo e o cenário e os objetos. (pelo menos foi 

Guía original de Starlight Skull. Todos sus créditos respectivos. Yo solo la traduje al español y simplifiqué el proceso, así que si quieren hacer el proceso paso a paso, véanlo en su guía. 

The original series has 6 games, out of which only 2 are released on Steam. So, I made some scripts to get other unreleased versions, officially available only for Android and as online game.