1st IMPORTNAT THING
You can not legally win the game, you need to enable cheats to pass the first 7 levels. (actually 6, there is no 7th level, that's why you need cheats) Just enable them and get after level 1.6 to level 2.1
2nd IMPORTANT THING
I rate it 5 stars in case of porn game (on this site, cuz witcher 3 is better ofc but it's not gonna be here), 2 stars in case of actual porn,5+2/2=7/2=3,5 rounded up to 4 because that's how math works.
Now to the actual review.
The only boner you gonna get is always going to be followed by a sentence "why the fuck do I get this boner?" Answering that question is on you, buddy.
If there would be something to fap about then this game would truly be wonderful. The mechanics are the best you could see on this site when it comes to a side-scroller. You NEVER get actually PUNISHED for watching the porn scenes. It's not that you are immortal, oh no, that's also not the case. This game has an intelligent way of calculating it, you can get fucked all the time with no drawbacks BUT you are only going to lose life if you fall off the map. (and few other ways that you will easily discover during the game if you decide to play it)
And even if you actually do happen to fall out 3 times (or whatever the health count u have) then you don't entirely get punished for losing all your life. Let's be honest, getting into sexual slavery in that sort of game is actually pretty cool if you can escape it just by walking out of the door... and getting a lewd clothes.
You can get different endings depending on how many times you get fucked. But you probably won't want to wait for that long so you will just enable cheats and watch the endings in the gallery like a normal person.
There's also the plot, which is simple and gets handed to you in first few seconds of the game, which is "Mario lost and is inprisoned by bowser, he is going to destroy everything and that weird-ass yellow dinosaur flying on a cloud made some kind of ritual so everything is lewd. All depend on you, Peach." After character creation and getting out of your bedroom you will be told by a certain toad that "Your body can also be used as a viable weapon." and that's how it goes.
The toad of course meant that you should get fucked to win but you can just break all your opponents necks by jumping on top of them like a dominatrix. What is really fun is that you get a role-reversal in which enemies fall unconscious to ever-craving nymphomaniac while you... well... you can never be satisfied... Which is damn cool.
To the bad side...
The scenes are... bizzare in a bad way (no deviations, just mario characters having sex which is fucked up all in itself... unless rule34 is a deviation itself then... oh my... this is great) There are multiple bugs along the way, and if you play on a better PC you will encounter them less (don't ask how I know that one) because if the lags are smaller then the game will be less likely to have you run inside a wall end get stuck. And you gonna cheat to pass the game at all.
Anyway, here's all searched link for the cheats, and the original site:
https://ivanaedler.github.io/MIMPUT/index.html