Mysterious Order is the second stage in Intrepid Cats.
Starts off with two each of buffed Mistress Celeboodles and Maawths. Once the enemy base is damaged, a cluster of Metal Doges spawn, along with bigger threats of 3 Ursamajors, 2 Calamaries, 3 Owlbrows, and 5 Cyberhorns, all extremely buffed save for the 6 Metal Doges. Very hard without strong Long Distance or Anti-Alien units like Aphrodite, Little Leaguer, and Hayabusa.
Stall the first four alien enemies. If a player has Aphrodite, she will pretty much guarantee a win, as she trashes the Aliens from excellent range. Hayabusa is also quite helpful, as he has long-distance attacks and criticals, that can effectively take out Calamary and the Metal Doges. If not, then try using Baseball Cat from the stage Honey Trap. Stack him against the Celeboodles, and he will kill the Maawths. A massive stack of him will clear out the heavy alien stacks once the base is hit.
If a player does not have Aphrodite or Baseball, then consider killing the Celeboodles with minimal amounts of Macho Legs/Crazed Sexy Legs, then desync the Maawths with he Cannon and slowly build up a pair of Li'l Nyandams as he outranges all of the enemies in the stage, and can be a great support. The shockwaves from Crazed Sexy Legs and the Long Distance attacks of Red Riding Mina are also helpful in taking out the Calamaries. Psychocat could also help with slowing the extremely steroid Cyberhorns (who have over one million health in 3-star!), as can Gato Amigo with knockback.
Beware of the Metal Doges, if they can't be stalled, they will push towards the base killing all your important cats, so make sure you have some critical hitters that don't get hit by the other aliens: e.g. Space Cat, or make sure your meatshields can handle both the Metal Doges and the buffed aliens.