An IF implementation of a fairly common videogame trope: eat things to get bigger so that you can eat bigger things. Mangiasaur is a world with the same bright, cartoony colours and magical-logic you'd expect in an early-aughts console game. There are a few notes which come across a shade more darkly, but mostly it's pure entertainment: don't expect involved puzzles, deep content or elegant design, but you will get light humour, satisfying gameplay and occasionally lovely notes of setting.
Adapting videogame mechanics to IF poses a number of problems, and one of the biggest is repetition. IF isn't really well-suited to problems of the 'kill 10 rats' type; the paradigm is hand-crafted, individual scenarios. Mangiasaur takes pretty much the path you'd expect; you don't need to eat a dozen critters to level up, and the challenge is more about finding and identifying your next target, or getting at them with light puzzles. A simple map and a low challenge level maintain a brisk pace.
So: fun, charming. Totally inconsequential, but sometimes that's what you need.