The film is being shot in Masai Mara, a large game reserve in south-western Kenya.
"Had an action sequence in the jungles! And we had to crawl! I had a hundred thorns in my hand. Just wonder how the animals don't get pricked," the 30-year-old posted on tweeter.
"Shortcut Romeo" is being directed and produced by Susi Ganeshan and it is a remake of his 2006 Tamil film "Thiruttu Payale". In the film, Puja Gupta plays Neil's love interest, while Ameesha has been cast in a negative role.
Neil, who was last seen in multi-starrer movie "Players", left for Kenya Jan 26.
"Ok so we had to scoot back into our safari vehicles because a group of 10 lionesses have gotten out to hunt antelopes. The pain of the thorn pricks just vanished seeing this," he further tweeted.
He is not only playing the lead role in the movie, but will also give voice to one of the songs. This is not the first time that Neil has turned singer. He had previously sung the title track for "Aa Dekhen Zara" and later gave his voice to a song in "Jail".