But this isn't a merger of two companies: Razer cherry-picked the pieces of OUYA that it bought, and as for the rest, the OP states that "... Ouya will cease to exist as a company following the Razer acquisition."
Now if the remaining shell of OUYA could pay off all remaining obligations, then these developers would get paid what they're due, and any money left over would go to the owners. But this from the OP "... they will not get the rest of the money they were owed because Ouya will cease to exist ..." implies that the money to pay all obligations isn't there. Which (as far as I can tell) means a Chapter 7 bankruptcy for what remains of OUYA.
This is a point where the details of the contracts matter a lot, but they're likely to be behind almost all other creditors in the pecking order. Worse, the ones who signed the updated contracts (because they were further along their release cycle) will be behind those who didn't. The devs who were more committed to the platform will be the deepest in the hole. And litigation, even if they were to win, is unlikely to help then: it is slow, and the money may just not be there. The devs will need to find alternative sources of funding, and may face bankruptcy themselves if they do not.