20w0 Keeper

20w0 Keeper is a game where you get a maths equation and has to solve it using the animals in your zoo! Each animal has a value corresponding to how much the audience love them, and you need to match the animals you're given with the pluses, minuses and other maths symbols to get 20! But oh no, some of the animals you don't need to solve the equation got out of their pens? How are you going to avert this crisis?! You'd better think fast, the clock is ticking!

Features 20 levels of maths puzzles! You can deal with pluses and minuses, sure, but what are you gonna do with square roots? Min-and-max operators? Powers of 2? Unknown operators where you need to experiment a bit to see what happens to the numbers you stuff into the equation?

An entry for the GameMaker 20 year anniversary jam. As per the jam's rules, the source code is included for free!  Download it and have fun! I doubt you can learn any good coding practices from the rushed, buggy source, but feel free to try :P