The game itself was very fun at the start. Getting to play as sans instead of the human was a very creative concept. I also loved the idea of being able to play as different monsters such as undyne, asgore and even flowey.
Only downside is some of the monsters had some extremely broken attacks that could make you clear the hardest difficulty on your first try. The playable monsters I'm talking about are sans and flowey. For sans all I had to do was spam Ghaster Blaster + blue heart combo in order to beat all difficulties first try. Flowey on the other hand was even more broken. Playing as flowey I saw that this character lacked a cool down and I soon realized that I could infinitely use a move called vine-whip. With this bullshit move I was able to freeze an enemy in place forever and wait till it dies from stun damage. Now you could just stay away from those 2 broken characters and play someone like papyrus or undyne. However all the other characters that aren't sans or flowey are so shit that it's not even worth purchasing them from the shop. For starters Undyne does NO DAMAGE AT ALL and all her moves can be blocked so easily. While papyrus only has 2 GARBAGE moves that he can attack the enemy with.
Lastly this game lacks enemy's to face off against. Like literally Chara is the only enemy you’ll face the entire game which can make gameplay dull and repetitive.
Only reason I decided to give this game 2 stars and not 0 was because it has some nice animations for each character and I liked it's pixel design